Words (or words that have the same definition) The definition is case sensitive (Optional) Image to display with the definition [Not displayed in Glossary, only in pop-up on pages] (Optional) Caption for Image (Optional) External or Internal Link (Optional) Source for Definition (Eg. "Genetic, Hereditary, DNA ...") (Eg. "Relating to genes or heredity") NaN The infamous double helix https://bio.libretexts.org/ CC-BY-SA; Delmar Larsen Word(s) Definition Image Caption Link Source absolute zero (0 K) The lowest possible temperature that can be theoretically achieved; it corresponds to −273.15°C. NaN NaN NaN NaN absorption spectrum A spectrum produced by the absorption of light by ground-state atoms. NaN NaN NaN NaN acid ionization constant (Ka) An equilibrium constant for the ionization (dissociation) of a weak acid (HA) with water, HA(aq) + H2O(l) ⇌ H3O(aq) + A−(aq), in which the concentration of water is treated as a constant: Ka = [H3O+][A−]/[HA]. NaN NaN NaN NaN acid rain Precipitation that is dramatically more acidic because of human activities. NaN NaN NaN NaN acid–base indicator A compound added in small amounts to an acid–base titration to signal the equivalence point by changing color. NaN NaN NaN NaN actinides Any of the 14 elements between Z=90 (thorium) and Z=103 (lawrencium). NaN NaN NaN NaN activation energy (Ea) The energy barrier or threshold that corresponds to the minimum amount of energy the particles in a reaction must have to react when they colllide. NaN NaN NaN NaN activity (A) The decrease in the number of a radioisotope’s nuclei per unit time: A=−ΔN/Δt. NaN NaN NaN NaN adduct The product of a reaction between a Lewis acid and a Lewis base with a coordinate covalent bond. NaN NaN NaN NaN aerosols A dispersion of solid or liquid particles in a gas. NaN NaN NaN NaN alcohol A class of organic compounds obtained by replacing one or more of the hydrogen atoms of a hydrocarbon with an −OH group. NaN NaN NaN NaN aliphatic hydrocarbons Alkanes, alkenes, alkynes, and cyclic hydrocarbons (hydrocarbons that are not aromatic). NaN NaN NaN NaN amalgams A solution (usually a solid solution) of a metal in liquid mercury. NaN NaN NaN NaN amine An organic compound that has the general formula RNH2, where R is an alkyl group. Amines, like ammonia, are bases. NaN NaN NaN NaN amorphous solid A solid with no particular structural order. NaN NaN NaN NaN amphiprotic Substances that can behave as either an acid or a base in a chemical reaction, depending on the nature of the other reactant(s). NaN NaN NaN NaN amphoteric When substances can behave as both an acid and a base. NaN NaN NaN NaN amplification mechanism A process by which elements that are present in trace amounts can exert large effects on the health of an organism. NaN NaN NaN NaN anions An ion that has fewer protons than electrons, resulting in a net negative charge. NaN NaN NaN NaN anisotropic An arrangement of molecules in which their properties depend on the direction they are measured. NaN NaN NaN NaN antibonding molecular orbital A molecular orbital that forms when atomic orbitals or orbital lobes of opposite sign interact to give decreased electron probability between the nuclei due to destructuve reinforcement of the wave functions. NaN NaN NaN NaN aqueous solution A solution in which water is the solvent. NaN NaN NaN NaN aromatic hydrocarbons An unsaturated hydrocarbon consisting of a ring of six carbon atoms with alternating single and double bonds. NaN NaN NaN NaN Arrhenius equation An expression that summarizes the collision model of chemical kinetics: k=Ae−Ea/RT. NaN NaN NaN NaN atmosphere (atm) Also referred to as standard atmospheric pressure, it is the atmospheric pressure required to support a column of mercury exactly 760 mm tall. NaN NaN NaN NaN atmosphere (atm) Also referred to as standard atmospheric pressure, it is the atmospheric pressure required to support a column of mercury exactly 760 mm tall. NaN NaN NaN NaN atomic mass unit (amu) One-twelfth of the mass of one atom of C12; 1 amu = 1.66 × 10−24g. NaN NaN NaN NaN atomic mass unit (amu) One-twelfth of the mass of one atom of C12; 1 amu = 1.66 × 10−24g. NaN NaN NaN NaN atomic orbital A wave function with an allowed combination of n, l., and ml quantum numbers. NaN NaN NaN NaN atomic orbital A wave function with an allowed combination of n, l., and ml quantum numbers. NaN NaN NaN NaN atoms The fundamental, individual particles of which matter is composed. NaN NaN NaN NaN atoms The fundamental, individual particles of which matter is composed. NaN NaN NaN NaN aufbau principle The process used to build up the periodic table by adding protons one by one to the nucleus and adding the corresponding electrons to the lowest-energy orbital available without violating the Pauli exclusion principle. NaN NaN NaN NaN aufbau principle The process used to build up the periodic table by adding protons one by one to the nucleus and adding the corresponding electrons to the lowest-energy orbital available without violating the Pauli exclusion principle. NaN NaN NaN NaN average reaction rate The reaction rate calculated for a given time interval from the concentrations of either the reactant or one of the products at the beginning of the interval time (t0) and at the end of the interval (t1). NaN NaN NaN NaN average reaction rate The reaction rate calculated for a given time interval from the concentrations of either the reactant or one of the products at the beginning of the interval time (t0) and at the end of the interval (t1). NaN NaN NaN NaN Avogadro’s law A law that states that at constant temperature and pressure, the volume of a sample of gas is directly proportional to the number of moles of gas in the sample. NaN NaN NaN NaN Avogadro’s law A law that states that at constant temperature and pressure, the volume of a sample of gas is directly proportional to the number of moles of gas in the sample. NaN NaN NaN NaN Avogadro’s number The number of units (e.g., atoms, molecules, or formula units) in 1 mol: 6.022×1023. NaN NaN NaN NaN Avogadro’s number The number of units (e.g., atoms, molecules, or formula units) in 1 mol: 6.022×1023. NaN NaN NaN NaN azimuthal quantum number (l) One of three quantum numbers that discribes the shape of the region of space occupied by an electron. NaN NaN NaN NaN azimuthal quantum number (l) One of three quantum numbers that discribes the shape of the region of space occupied by an electron. NaN NaN NaN NaN band gap The difference in energy between the highest level of one energy band and the lowest level of the band above it, which represents a set of forbidden energies that do not correspond to any allowed combinations of atomic orbitals. NaN NaN NaN NaN band gap The difference in energy between the highest level of one energy band and the lowest level of the band above it, which represents a set of forbidden energies that do not correspond to any allowed combinations of atomic orbitals. NaN NaN NaN NaN band theory A theory used to describe the bonding in metals and semiconductors. NaN NaN NaN NaN band theory A theory used to describe the bonding in metals and semiconductors. NaN NaN NaN NaN bandwidth The difference in energy between the highest and lowest energy levels in an energy band. NaN NaN NaN NaN bandwidth The difference in energy between the highest and lowest energy levels in an energy band. NaN NaN NaN NaN barometer A device used to measure atmospheric pressure. NaN NaN NaN NaN barometer A device used to measure atmospheric pressure. NaN NaN NaN NaN base A substance that produces one or more hydroxide ions (OH−) and a cation when dissolved in aqueous solution, thereby forming a basic solution. NaN NaN NaN NaN base A substance that produces one or more hydroxide ions (OH−) and a cation when dissolved in aqueous solution, thereby forming a basic solution. NaN NaN NaN NaN base ionization constant An equilibrium constant for the reaction of a weak base (B) with water, in which the concentration of water is treated as a constant. Abbreviation: Kb NaN NaN NaN NaN base ionization constant (Kb) An equilibrium constant for the reaction of a weak base (B) with water, B(aq) + H2O(l) ⇌ BH+(aq) + OH−(aq), in which the concentration of water is treated as a constant: Kb = [BH+][OH−]/[B]. NaN NaN NaN NaN bases A substance that produces one or more hydroxide ions (OH−) and a cation when dissolved in aqueous solution, thereby forming a basic solution. NaN NaN NaN NaN bases A substance that produces one or more hydroxide ions (OH−) and a cation when dissolved in aqueous solution, thereby forming a basic solution. NaN NaN NaN NaN bilayers A two-dimensional sheet consisting of a double layer of phospholipid molecules arranged tail to tail. NaN NaN NaN NaN bilayers A two-dimensional sheet consisting of a double layer of phospholipid molecules arranged tail to tail. NaN NaN NaN NaN binary ionic compound An ionic compound that contains only two elements, one present as a cation and one as an anion. NaN NaN NaN NaN binary ionic compound An ionic compound that contains only two elements, one present as a cation and one as an anion. NaN NaN NaN NaN biochemistry The application of chemistry to the study of biological processes. NaN NaN NaN NaN biochemistry The application of chemistry to the study of biological processes. NaN NaN NaN NaN blackbody radiation Electromagnetic radiation whose wavelength and color depends on the temperature of the object. NaN NaN NaN NaN blackbody radiation Electromagnetic radiation whose wavelength and color depends on the temperature of the object. NaN NaN NaN NaN boiling point elevation (ΔTb) The difference between the boiling point of a solution and the boiling point of the pure solvent. NaN NaN NaN NaN boiling point elevation (ΔTb) The difference between the boiling point of a solution and the boiling point of the pure solvent. NaN NaN NaN NaN Boltzmann distributions A curve that shows the distribution of molecular speeds at a given temperature. NaN NaN NaN NaN Boltzmann distributions A curve that shows the distribution of molecular speeds at a given temperature. NaN NaN NaN NaN bomb calorimeter A device used to measure energy changes in chemical processes. NaN NaN NaN NaN bomb calorimeter A device used to measure energy changes in chemical processes. NaN NaN NaN NaN bond distance(r0) The optimal internuclear distance between two bonded atoms. NaN NaN NaN NaN bond distance(r0) The optimal internuclear distance between two bonded atoms. NaN NaN NaN NaN bond energy The enthalpy change that occurs when a given bond in a gaseous molecule is broken. NaN NaN NaN NaN bond energy The enthalpy change that occurs when a given bond in a gaseous molecule is broken. NaN NaN NaN NaN bond order The number of electron pairs that hold two atoms together. NaN NaN NaN NaN bond order The number of electron pairs that hold two atoms together. NaN NaN NaN NaN bond order One-half the net number of bonding electrons in a molecule. NaN NaN NaN NaN bond order One-half the net number of bonding electrons in a molecule. NaN NaN NaN NaN Born–Haber cycle A thermochemical cycle that decribes the process in which an ionic solid is conceptually formed from its component elements in a stepwise manner. NaN NaN NaN NaN Born–Haber cycle A thermochemical cycle that decribes the process in which an ionic solid is conceptually formed from its component elements in a stepwise manner. NaN NaN NaN NaN Boyle’s law A law that states that at constant temperature, the volume of a fixed amount of a gas is inversely proportional to its pressure. NaN NaN NaN NaN Boyle’s law A law that states that at constant temperature, the volume of a fixed amount of a gas is inversely proportional to its pressure. NaN NaN NaN NaN Bragg equation The equation that describes the relationship between two x-ray beams diffracted from different planes of atoms: 2d sin θ=nλ. NaN NaN NaN NaN Bragg equation The equation that describes the relationship between two x-ray beams diffracted from different planes of atoms: 2d sin θ=nλ. NaN NaN NaN NaN buffer capacity The amount of strong acid or strong base that a buffer solution can absorb before the pH changes dramatically. NaN NaN NaN NaN Buffers Solutions that maintain a relatively constant pH when an acid or a base is added. NaN NaN NaN NaN Calorie A unit used to indicate the caloric content of food. It is equal to 1 kilocalorie (1 kcal). NaN NaN NaN NaN Calorie A unit used to indicate the caloric content of food. It is equal to 1 kilocalorie (1 kcal). NaN NaN NaN NaN calories (cal) A non-SI unit of energy: 1 cal = 4.184 J exactly. NaN NaN NaN NaN calories (cal) A non-SI unit of energy: 1 cal = 4.184 J exactly. NaN NaN NaN NaN Calorimetry A set of techniques used to measure enthalpy changes in chemical processes. NaN NaN NaN NaN Calorimetry A set of techniques used to measure enthalpy changes in chemical processes. NaN NaN NaN NaN capillary action The tendency of a polar liquid to rise against gravity into a small-diameter glass tube. NaN NaN NaN NaN capillary action The tendency of a polar liquid to rise against gravity into a small-diameter glass tube. NaN NaN NaN NaN carbon cycle The distribution and flow of carbon throughout the planet. NaN NaN NaN NaN carbon cycle The distribution and flow of carbon throughout the planet. NaN NaN NaN NaN carboxylic acids An organic compound that contains an −OH group covalently bonded to the carbon atom of a carbonyl group. The general formula of a carboxylic acid is RCO2H. In water a carboxylic acid dissociates to produce an acidic solution. NaN NaN NaN NaN carboxylic acids An organic compound that contains an −OH group covalently bonded to the carbon atom of a carbonyl group. The general formula of a carboxylic acid is RCO2H. In water a carboxylic acid dissociates to produce an acidic solution. NaN NaN NaN NaN catalysis The acceleration of a chemical reaction by a catalyst. NaN NaN NaN NaN catalysis The acceleration of a chemical reaction by a catalyst. NaN NaN NaN NaN catalysts A substance that participates in a reaction and causes it to occur more rapidly but that can be recovered unchanged at the end of the reaction and reused. Catalysts may also control which products are formed in a reaction. NaN NaN NaN NaN catalysts A substance that participates in a reaction and causes it to occur more rapidly but that can be recovered unchanged at the end of the reaction and reused. Catalysts may also control which products are formed in a reaction. NaN NaN NaN NaN cell A collection of molecules, capable of reproducing itself, that is surrounded by a phospholipid bilayer. NaN NaN NaN NaN cell A collection of molecules, capable of reproducing itself, that is surrounded by a phospholipid bilayer. NaN NaN NaN NaN ceramic Any nonmetallic inorganic solid that is strong eneough to be used in structural applications. NaN NaN NaN NaN ceramic Any nonmetallic inorganic solid that is strong eneough to be used in structural applications. NaN NaN NaN NaN Ceramic-matrix composites A composite consisting of reinforcing fibers embedded in a ceramic matrix. NaN NaN NaN NaN Ceramic-matrix composites A composite consisting of reinforcing fibers embedded in a ceramic matrix. NaN NaN NaN NaN cesium chloride structure The unit cell for many ionic compounds with relatively large cations and a 1:1 cation:anion ratio. NaN NaN NaN NaN cesium chloride structure The unit cell for many ionic compounds with relatively large cations and a 1:1 cation:anion ratio. NaN NaN NaN NaN chain reactions A reaction mechanism in which one or more elementary reactions that contain a highly reactive species repeat again and again during the reaction process. NaN NaN NaN NaN chain reactions A reaction mechanism in which one or more elementary reactions that contain a highly reactive species repeat again and again during the reaction process. NaN NaN NaN NaN chalcogens The elements in group 16 of the periodic table. NaN NaN NaN NaN chalcogens The elements in group 16 of the periodic table. NaN NaN NaN NaN change in enthalpy (ΔH) At constant pressure, the amount of heat transferred from the surroundings to the system or vice versa: .ΔH= qp. NaN NaN NaN NaN change in enthalpy (ΔH) At constant pressure, the amount of heat transferred from the surroundings to the system or vice versa: .ΔH= qp. NaN NaN NaN NaN Charles’s law A law that states that at constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute temperature (in kelvins). NaN NaN NaN NaN Charles’s law A law that states that at constant pressure, the volume of a fixed amount of gas is directly proportional to its absolute temperature (in kelvins). NaN NaN NaN NaN chemical bonds An attractive interaction between atoms that holds them together in compounds. NaN NaN NaN NaN chemical bonds An attractive interaction between atoms that holds them together in compounds. NaN NaN NaN NaN chemical change A process in which the chemical composition of one or more substances is altered. NaN NaN NaN NaN chemical change A process in which the chemical composition of one or more substances is altered. NaN NaN NaN NaN chemical energy One of the five forms of energy, chemical energy is stored within a chemical compound because of a particular arrangement of atoms. The other four forms of energy are radiant, thermal, nuclear, and electrical. NaN NaN NaN NaN chemical energy One of the five forms of energy, chemical energy is stored within a chemical compound because of a particular arrangement of atoms. The other four forms of energy are radiant, thermal, nuclear, and electrical. NaN NaN NaN NaN chemical equilibrium The point at which the forward and reverse reaction rates become the same so that the net composition of the system no longer changes with time. NaN NaN NaN NaN Chemical properties The characteristic ability of a substance to react to form new substances. NaN NaN NaN NaN Chemical properties The characteristic ability of a substance to react to form new substances. NaN NaN NaN NaN chemical reactions A process in which a substance is converted to one or more other substances with different compositions and properties. NaN NaN NaN NaN Chemistry The study of matter and the changes that material substances undergo. NaN NaN NaN NaN Chemistry The study of matter and the changes that material substances undergo. NaN NaN NaN NaN cholesteric phase One of three different ways that most liquid crystals can orient themselves. The molecules are arranged in planes (similar to the smectic phase), but each layer is rotated by a certain amount with respect to those above and below it, giving it a helical structure. NaN NaN NaN NaN cholesteric phase One of three different ways that most liquid crystals can orient themselves. The molecules are arranged in planes (similar to the smectic phase), but each layer is rotated by a certain amount with respect to those above and below it, giving it a helical structure. NaN NaN NaN NaN Clausius–Clapeyron equation A linear relationship that expresses the nonlinear relationship between the vapor pressure of a liquid and temperature: ln P=−ΔHvap/RT+C, where P is pressure, ΔHvap is the heat of vaporization, R is the universal gas constant, T is the absolute temperature, and C is a constant. The Clausius–Clapeyron equation can be used to calculate the heat of vaporization of a liquid from its measured vapor pressure at two or more temperatures. NaN NaN NaN NaN Clausius–Clapeyron equation A linear relationship that expresses the nonlinear relationship between the vapor pressure of a liquid and temperature: ln P=−ΔHvap/RT+C, where P is pressure, ΔHvap is the heat of vaporization, R is the universal gas constant, T is the absolute temperature, and C is a constant. The Clausius–Clapeyron equation can be used to calculate the heat of vaporization of a liquid from its measured vapor pressure at two or more temperatures. NaN NaN NaN NaN Coal A complex solid material derived primarily from plants that died and were buried hundreds of millions of years ago and were subsequently subjected to high temperatures and pressures. It is used as a fuel. NaN NaN NaN NaN Coal A complex solid material derived primarily from plants that died and were buried hundreds of millions of years ago and were subsequently subjected to high temperatures and pressures. It is used as a fuel. NaN NaN NaN NaN coefficient A number greater than 1 preceding a formula in a balanced chemical equation and indicating the number of atoms, molecules, or formula units of a reactant or a product. NaN NaN NaN NaN coefficient A number greater than 1 preceding a formula in a balanced chemical equation and indicating the number of atoms, molecules, or formula units of a reactant or a product. NaN NaN NaN NaN colligative properties A property of a solution that depends primarily on the number of solute particles rather than the kind of solute particles. NaN NaN NaN NaN colligative properties A property of a solution that depends primarily on the number of solute particles rather than the kind of solute particles. NaN NaN NaN NaN colloid A heterogeneous mixture of particles with diameters of about 2–500 nm that are distributed throughout a second phase and do not separate from the dispersing phase on standing. NaN NaN NaN NaN colloid A heterogeneous mixture of particles with diameters of about 2–500 nm that are distributed throughout a second phase and do not separate from the dispersing phase on standing. NaN NaN NaN NaN combustion The burning of a material in an oxygen atmosphere. NaN NaN NaN NaN combustion The burning of a material in an oxygen atmosphere. NaN NaN NaN NaN combustion reaction An oxidation–reduction reaction in which the oxidant is O2. NaN NaN NaN NaN combustion reaction An oxidation–reduction reaction in which the oxidant is O2. NaN NaN NaN NaN common ion effect The shift in equilibrium that results when a strong electrolyte containing one ion in common with a reaction system that is at equilibrium is added to the system. NaN NaN NaN NaN complete ionic equation A chemical equation that shows which ions and molecules are hydrated and which are present in other forms and phases. NaN NaN NaN NaN complete ionic equation A chemical equation that shows which ions and molecules are hydrated and which are present in other forms and phases. NaN NaN NaN NaN Composite materials A material that consists of at least two distinct phases: the matrix (which constitutes the bulk of the material) and fibers or granules that are embedded within the matrix. NaN NaN NaN NaN Composite materials A material that consists of at least two distinct phases: the matrix (which constitutes the bulk of the material) and fibers or granules that are embedded within the matrix. NaN NaN NaN NaN concentration The quantity of solute that is dissolved in a particular quantity of solvent or solution. NaN NaN NaN NaN concentration The quantity of solute that is dissolved in a particular quantity of solvent or solution. NaN NaN NaN NaN concentration The quantity of solute that is dissolved in a particular quantity of solvent or solution. NaN NaN NaN NaN concentration The quantity of solute that is dissolved in a particular quantity of solvent or solution. NaN NaN NaN NaN condensation The physical process by which atoms or molecules in the vapor phase enter the liquid phase. NaN NaN NaN NaN condensation The physical process by which atoms or molecules in the vapor phase enter the liquid phase. NaN NaN NaN NaN conduction band The band of empty molecular orbitals in a semiconductor. NaN NaN NaN NaN conduction band The band of empty molecular orbitals in a semiconductor. NaN NaN NaN NaN conjugate acid–base pair An acid and a base that differ by only one hydrogen ion. NaN NaN NaN NaN conjugate acid–base pair An acid and a base that differ by only one hydrogen ion. NaN NaN NaN NaN conjugate acid–base pairs An acid and a base that differ by only one hydrogen ion. All acid–base reactions involve two conjugate acid–base pairs, the Brønsted–Lowry acid and the base it forms after donating its proton, and the Brønsted–Lowry base and the acid it forms after accepting a proton. NaN NaN NaN NaN conjugate acid–base pairs An acid and a base that differ by only one hydrogen ion. All acid–base reactions involve two conjugate acid–base pairs, the Brønsted–Lowry acid and the base it forms after donating its proton, and the Brønsted–Lowry base and the acid it forms after accepting a proton. NaN NaN NaN NaN constant-pressure calorimeter A device used to measure enthalpy changes in chemical processes at constant pressure. NaN NaN NaN NaN constant-pressure calorimeter A device used to measure enthalpy changes in chemical processes at constant pressure. NaN NaN NaN NaN Cooper pairs Pairs of electrons that migrate through a superconducting material as a unit. NaN NaN NaN NaN Cooper pairs Pairs of electrons that migrate through a superconducting material as a unit. NaN NaN NaN NaN coordinate covalent bond A covalent bond in which both electrons come from the same atom. NaN NaN NaN NaN coordinate covalent bond A covalent bond in which both electrons come from the same atom. NaN NaN NaN NaN coordination number The number of nearest neighbors in a solid structure. NaN NaN NaN NaN coordination number The number of nearest neighbors in a solid structure. NaN NaN NaN NaN covalent atomic radius (rcov) Half the distance between the nuclei of two like atoms joined by a covalent bond in the same molecule. NaN NaN NaN NaN covalent atomic radius (rcov) Half the distance between the nuclei of two like atoms joined by a covalent bond in the same molecule. NaN NaN NaN NaN covalent bond The electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons they share. NaN NaN NaN NaN covalent bond The electrostatic attraction between the positively charged nuclei of the bonded atoms and the negatively charged electrons they share. NaN NaN NaN NaN Covalent solids A solid that consists of two- or three-dimensional networks of atoms held together by covalent bonds. NaN NaN NaN NaN Covalent solids A solid that consists of two- or three-dimensional networks of atoms held together by covalent bonds. NaN NaN NaN NaN critical point The combination of the critical temperature and the critical pressure of a substance. NaN NaN NaN NaN critical point The combination of the critical temperature and the critical pressure of a substance. NaN NaN NaN NaN crown ethers Cyclic polyether with four or more oxygen atoms separated by two or three carbon atoms. All crown ethers have a central cavity that can accommodate a metal ion coordinated to the ring of oxygen atoms. NaN NaN NaN NaN crown ethers Cyclic polyether with four or more oxygen atoms separated by two or three carbon atoms. All crown ethers have a central cavity that can accommodate a metal ion coordinated to the ring of oxygen atoms. NaN NaN NaN NaN cryogenic liquids An ultracold liquid formed from the liquefaction of gases. NaN NaN NaN NaN cryogenic liquids An ultracold liquid formed from the liquefaction of gases. NaN NaN NaN NaN Cryptands Consisting of three (–OCH2CH2O–)n chains connected by two nitrogen atoms, cryptands have a central cavity that can encapsulate a metal ion coordinated to the oxygen and nitrogen atoms. NaN NaN NaN NaN Cryptands Consisting of three (–OCH2CH2O–)n chains connected by two nitrogen atoms, cryptands have a central cavity that can encapsulate a metal ion coordinated to the oxygen and nitrogen atoms. NaN NaN NaN NaN Crystallization A physical process used to separate homogeneous mixtures (solutions) into their component substances. Crystallization separates mixtures based on differences in their solubilities. NaN NaN NaN NaN Crystallization A physical process used to separate homogeneous mixtures (solutions) into their component substances. Crystallization separates mixtures based on differences in their solubilities. NaN NaN NaN NaN cubic close-packed (ccp) structure One of two variants of the close-packed arrangement—the most efficient way to pack spheres in a lattice—in which the atomic positions alter from layer to layer in an ABCABC… pattern. NaN NaN NaN NaN cubic close-packed (ccp) structure One of two variants of the close-packed arrangement—the most efficient way to pack spheres in a lattice—in which the atomic positions alter from layer to layer in an ABCABC… pattern. NaN NaN NaN NaN cyclic hydrocarbon A hydrocarbon in which the ends of the carbon chain are connected to form a ring of covalently bonded carbon atoms. NaN NaN NaN NaN cyclic hydrocarbon A hydrocarbon in which the ends of the carbon chain are connected to form a ring of covalently bonded carbon atoms. NaN NaN NaN NaN Dalton’s law of partial pressures A law that states that the total pressure exerted by a mixture of gases is the sum of the partial pressures of component gases. NaN NaN NaN NaN Dalton’s law of partial pressures A law that states that the total pressure exerted by a mixture of gases is the sum of the partial pressures of component gases. NaN NaN NaN NaN defects Errors in an idealized crystal lattice. NaN NaN NaN NaN defects Errors in an idealized crystal lattice. NaN NaN NaN NaN Deformation A distortion that occurs when a dislocation moves through a crystal. NaN NaN NaN NaN Deformation A distortion that occurs when a dislocation moves through a crystal. NaN NaN NaN NaN degenerate Having the same energy. NaN NaN NaN NaN degenerate Having the same energy. NaN NaN NaN NaN density (d) An intensive property of matter, density is the mass per unit volume (usually expressed in g/cm3). At a given temperature, the density of a substance is a constant. NaN NaN NaN NaN density (d) An intensive property of matter, density is the mass per unit volume (usually expressed in g/cm3). At a given temperature, the density of a substance is a constant. NaN NaN NaN NaN dialysis A process that uses a semipermeable membrane with pores large enough to allow small solute molecules and solvent molecules to pass through but not large solute molecules. NaN NaN NaN NaN dialysis A process that uses a semipermeable membrane with pores large enough to allow small solute molecules and solvent molecules to pass through but not large solute molecules. NaN NaN NaN NaN dielectric constant (ε) A constant that expresses the ability of a bulk substance to decrease the electrostatic forces between two charged particles. NaN NaN NaN NaN dielectric constant (ε) A constant that expresses the ability of a bulk substance to decrease the electrostatic forces between two charged particles. NaN NaN NaN NaN dipole moment The product of the partial charge Q on the bonded atoms and the distance r between the partial charges: µ=Qr, where Q is measured in coulombs (C) and r in meters (m). NaN NaN NaN NaN dipole moment The product of the partial charge Q on the bonded atoms and the distance r between the partial charges: µ=Qr, where Q is measured in coulombs (C) and r in meters (m). NaN NaN NaN NaN dipole–dipole interactions A kind of intermolecular interaction (force) that results between molecules with net dipole moments. NaN NaN NaN NaN dipole–dipole interactions A kind of intermolecular interaction (force) that results between molecules with net dipole moments. NaN NaN NaN NaN Distillation A physical process used to separate homogeneous mixtures (solutions) into their component substances. Distillation makes use of differences in the volatilities of the component substances. NaN NaN NaN NaN Distillation A physical process used to separate homogeneous mixtures (solutions) into their component substances. Distillation makes use of differences in the volatilities of the component substances. NaN NaN NaN NaN edge dislocation A crystal defect that results from the insertion of an extra plane of atoms into part of the crystal lattice. NaN NaN NaN NaN edge dislocation A crystal defect that results from the insertion of an extra plane of atoms into part of the crystal lattice. NaN NaN NaN NaN effusion The escape of a gas through a small (usually microscopic) opening into an evacuated space. NaN NaN NaN NaN effusion The escape of a gas through a small (usually microscopic) opening into an evacuated space. NaN NaN NaN NaN electrical insulators A material that conducts electricity poorly because its valence bands are full. NaN NaN NaN NaN electrical insulators A material that conducts electricity poorly because its valence bands are full. NaN NaN NaN NaN electron affinity(EA) The energy change that occurs when an electron is added to a gaseous atom: E(g) + e−→E−(g). NaN NaN NaN NaN electron affinity(EA) The energy change that occurs when an electron is added to a gaseous atom: E(g) + e−→E−(g). NaN NaN NaN NaN electron configuration The arrangement of an element’s electrons in its atomic orbitals. NaN NaN NaN NaN electron configuration The arrangement of an element’s electrons in its atomic orbitals. NaN NaN NaN NaN electron density Electron distributions that are represented as standing waves. NaN NaN NaN NaN electron density Electron distributions that are represented as standing waves. NaN NaN NaN NaN electron sea Valence electrons that are delocalized throughout a metallic solid. NaN NaN NaN NaN electron sea Valence electrons that are delocalized throughout a metallic solid. NaN NaN NaN NaN electron shielding The effect by which electrons closer to the nucleus neutralize a portion of the positive charge of the nucleus and thereby decrease the attractive interaction between the nucleus and an electron father away. NaN NaN NaN NaN electron shielding The effect by which electrons closer to the nucleus neutralize a portion of the positive charge of the nucleus and thereby decrease the attractive interaction between the nucleus and an electron father away. NaN NaN NaN NaN electron spin The magnetic moment that results when an electron spins. Electrons have two possible orientations (spin up and spin down), which are described by a fourth quantum number (ms). NaN NaN NaN NaN electron spin The magnetic moment that results when an electron spins. Electrons have two possible orientations (spin up and spin down), which are described by a fourth quantum number (ms). NaN NaN NaN NaN Electron-deficient molecules A compound that has less than an octet of electrons around one atom. NaN NaN NaN NaN Electron-deficient molecules A compound that has less than an octet of electrons around one atom. NaN NaN NaN NaN electronegativity The relative ability of an atom to attract electrons to itself in a chemical compound. NaN NaN NaN NaN electronegativity The relative ability of an atom to attract electrons to itself in a chemical compound. NaN NaN NaN NaN elementary reaction Each of the complex series of reactions that take place in a stepwise fashion to convert reactants to products. NaN NaN NaN NaN elementary reaction Each of the complex series of reactions that take place in a stepwise fashion to convert reactants to products. NaN NaN NaN NaN Emulsions A dispersion of one liquid phase in another liquid with which it is immiscible. NaN NaN NaN NaN Emulsions A dispersion of one liquid phase in another liquid with which it is immiscible. NaN NaN NaN NaN endothermic A process in which heat (q) is transferred to a system from its surroundings. NaN NaN NaN NaN endothermic A process in which heat (q) is transferred to a system from its surroundings. NaN NaN NaN NaN endpoint The point in a titration at which an indicator changes color. NaN NaN NaN NaN endpoint The point in a titration at which an indicator changes color. NaN NaN NaN NaN energy-level diagram A schematic drawing that compares the energies of the molecular orbitals (bonding, antibonding, and nonbonding) with the energies of the parent atomic orbitals. NaN NaN NaN NaN energy-level diagram A schematic drawing that compares the energies of the molecular orbitals (bonding, antibonding, and nonbonding) with the energies of the parent atomic orbitals. NaN NaN NaN NaN enthalpy (H) The sum of a system’s internal energy E and the product of its pressure P and volume V: H=E+PV. NaN NaN NaN NaN enthalpy (H) The sum of a system’s internal energy E and the product of its pressure P and volume V: H=E+PV. NaN NaN NaN NaN Enthalpy of formation (ΔHf) The enthalpy change for the formation of 1 mol of a compound from its component elements. NaN NaN NaN NaN Enthalpy of formation (ΔHf) The enthalpy change for the formation of 1 mol of a compound from its component elements. NaN NaN NaN NaN enthalpy of reaction (ΔHrxn) The change in enthalpy that occurs during a chemical reaction. NaN NaN NaN NaN enthalpy of reaction (ΔHrxn) The change in enthalpy that occurs during a chemical reaction. NaN NaN NaN NaN enthalpy of sublimation (ΔHsub) The enthalpy change that accompanies the conversion of a solid directly to a gas. NaN NaN NaN NaN enthalpy of sublimation (ΔHsub) The enthalpy change that accompanies the conversion of a solid directly to a gas. NaN NaN NaN NaN enthalpy of sublimation(ΔHsub) The enthalpy change that accompanies the conversion of a solid directly to a gas. NaN NaN NaN NaN enthalpy of sublimation(ΔHsub) The enthalpy change that accompanies the conversion of a solid directly to a gas. NaN NaN NaN NaN entropy(S) The degree of disorder in a thermodynamic system. The greater the number of possible microstates for a system, the higher the entropy. NaN NaN NaN NaN entropy(S) The degree of disorder in a thermodynamic system. The greater the number of possible microstates for a system, the higher the entropy. NaN NaN NaN NaN enzyme A catalyst that occurs naturally in living organisms and catalyzes biological reactions. NaN NaN NaN NaN enzyme A catalyst that occurs naturally in living organisms and catalyzes biological reactions. NaN NaN NaN NaN Enzyme inhibitors Substances that decrease the reaction rate of an enzyme-catalyzed reaction by binding to a specific portion of the enzyme, thus slowing or preventing a reaction from occurring. NaN NaN NaN NaN Enzyme inhibitors Substances that decrease the reaction rate of an enzyme-catalyzed reaction by binding to a specific portion of the enzyme, thus slowing or preventing a reaction from occurring. NaN NaN NaN NaN enzymes Catalysts that occur naturally in living organisms and that catalyze biological reactions. NaN NaN NaN NaN enzymes Catalysts that occur naturally in living organisms and that catalyze biological reactions. NaN NaN NaN NaN equilibrium The point at which the rates of the forward and reverse reactions become the same, so that the net composition of the system no longer changes with time. NaN NaN NaN NaN equilibrium The point at which the rates of the forward and reverse reactions become the same, so that the net composition of the system no longer changes with time. NaN NaN NaN NaN equilibrium constant (K) The ratio of the rate constants for the forward reaction and the reverse reaction; that is, K=kf/kr. It is also the equilibrium constant calculated from solution concentrations: K=[C]c[D]d/[A]a[B]b for the general reaction aA+bB⇌cC+dD, in which each component is in solution. NaN NaN NaN NaN equilibrium constant (K) The ratio of the rate constants for the forward reaction and the reverse reaction; that is, K=kf/kr. It is also the equilibrium constant calculated from solution concentrations: K=[C]c[D]d/[A]a[B]b for the general reaction aA+bB⇌cC+dD, in which each component is in solution. NaN NaN NaN NaN equilibrium constant expression For a balanced chemical equation, the ratio is [C]c[D]d/[A]a[B]b for the general reaction aA+bB⇌cC+dD. NaN NaN NaN NaN equilibrium constant expression For a balanced chemical equation, the ratio is [C]c[D]d/[A]a[B]b for the general reaction aA+bB⇌cC+dD. NaN NaN NaN NaN equilibrium vapor pressure The pressure exerted by a vapor in dynamic equilibrium with its liquid. NaN NaN NaN NaN equilibrium vapor pressure The pressure exerted by a vapor in dynamic equilibrium with its liquid. NaN NaN NaN NaN equivalence point The point in a titration where a stoichiometric amount (i.e., the amount required to react completely with the unknown) of the titrant has been added. NaN NaN NaN NaN equivalence point The point in a titration where a stoichiometric amount (i.e., the amount required to react completely with the unknown) of the titrant has been added. NaN NaN NaN NaN equivalence point The point in a titration where a stoichiometric amount of the titrant has been added. NaN NaN NaN NaN essential elements Any of the 19 elements that are absolutely required in the human diet for survival. An additional seven elements are thought to be essential for humans. NaN NaN NaN NaN essential elements Any of the 19 elements that are absolutely required in the human diet for survival. An additional seven elements are thought to be essential for humans. NaN NaN NaN NaN Essential trace elements Elements that are required for the growth of most organisms. NaN NaN NaN NaN Essential trace elements Elements that are required for the growth of most organisms. NaN NaN NaN NaN evaporation (or vaporization) The physical process by which atoms or molecules in the liquid phase enter the gas or vapor phase. NaN NaN NaN NaN evaporation (or vaporization) The physical process by which atoms or molecules in the liquid phase enter the gas or vapor phase. NaN NaN NaN NaN exact numbers An integer obtained either by counting objects or from definitions (e.g., 1 in. = 2.54 cm). Exact numbers have infinitely many significant figures. NaN NaN NaN NaN exact numbers An integer obtained either by counting objects or from definitions (e.g., 1 in. = 2.54 cm). Exact numbers have infinitely many significant figures. NaN NaN NaN NaN excited state Any arrangement of electrons that is higher in energy than the ground state. NaN NaN NaN NaN excited state Any arrangement of electrons that is higher in energy than the ground state. NaN NaN NaN NaN exothermic A process in which heat (q) is transferred from a system to its surroundings. NaN NaN NaN NaN exothermic A process in which heat (q) is transferred from a system to its surroundings. NaN NaN NaN NaN expanded-valence molecules A compound with more than an octet of electrons around an atom. NaN NaN NaN NaN expanded-valence molecules A compound with more than an octet of electrons around an atom. NaN NaN NaN NaN f block The elements in the periodic table in which the (n − 2)f orbitals are being filled. NaN NaN NaN NaN f block The elements in the periodic table in which the (n − 2)f orbitals are being filled. NaN NaN NaN NaN face-centered cubic (fcc) A cubic unit cell with eight component atoms, molecules, or ions located at the corners of a cube plus an identical component in the center of each face of the cube. NaN NaN NaN NaN face-centered cubic (fcc) A cubic unit cell with eight component atoms, molecules, or ions located at the corners of a cube plus an identical component in the center of each face of the cube. NaN NaN NaN NaN fibers A particle of a synthetic polymer that is more than 100 times longer than it is wide. NaN NaN NaN NaN fibers A particle of a synthetic polymer that is more than 100 times longer than it is wide. NaN NaN NaN NaN first-order reaction A reaction whose rate is directly proportional to the concentration of one reactant. NaN NaN NaN NaN first-order reaction A reaction whose rate is directly proportional to the concentration of one reactant. NaN NaN NaN NaN formal charge The difference between the number of valence electrons in a free atom and the number of electrons assigned to it in a particular Lewis electron structure. NaN NaN NaN NaN formal charge The difference between the number of valence electrons in a free atom and the number of electrons assigned to it in a particular Lewis electron structure. NaN NaN NaN NaN formula mass The sum of the atomic masses of all the elements in the empirical formula, each multiplied by its subscript. NaN NaN NaN NaN formula mass The sum of the atomic masses of all the elements in the empirical formula, each multiplied by its subscript. NaN NaN NaN NaN formula unit The absolute grouping of atoms or ions represented by the empirical formula. NaN NaN NaN NaN formula unit The absolute grouping of atoms or ions represented by the empirical formula. NaN NaN NaN NaN fractional crystallization The separation of compounds based on their relative solubilities in a given solvent. NaN NaN NaN NaN fractional crystallization The separation of compounds based on their relative solubilities in a given solvent. NaN NaN NaN NaN freezing point depression (ΔTf) The difference between the freezing point of a pure solvent and the freezing point of the solution. NaN NaN NaN NaN freezing point depression (ΔTf) The difference between the freezing point of a pure solvent and the freezing point of the solution. NaN NaN NaN NaN Frenkel defect A defect in an ionic lattice that occurs when one of the ions is in the wrong position. NaN NaN NaN NaN Frenkel defect A defect in an ionic lattice that occurs when one of the ions is in the wrong position. NaN NaN NaN NaN frequency factor A constant in the Arrhenius equation, it converts concentrations to collisions per second. NaN NaN NaN NaN frequency factor A constant in the Arrhenius equation, it converts concentrations to collisions per second. NaN NaN NaN NaN fundamental The lowest-energy standing wave. NaN NaN NaN NaN fundamental The lowest-energy standing wave. NaN NaN NaN NaN fusion (or melting) The conversion of a solid to a liquid. NaN NaN NaN NaN fusion (or melting) The conversion of a solid to a liquid. NaN NaN NaN NaN gas constant A proportionality constant that is used in the ideal gas law. NaN NaN NaN NaN gas constant A proportionality constant that is used in the ideal gas law. NaN NaN NaN NaN glass An amorphous, translucent solid. A glass is a solid that has been cooled too quickly to form ordered crystals. NaN NaN NaN NaN glass An amorphous, translucent solid. A glass is a solid that has been cooled too quickly to form ordered crystals. NaN NaN NaN NaN Graham’s law A law that states that the rate of effusion of a gaseous substance is inversely proportional to the square root of its molar mass. NaN NaN NaN NaN Graham’s law A law that states that the rate of effusion of a gaseous substance is inversely proportional to the square root of its molar mass. NaN NaN NaN NaN grain boundary The place where two grains in a solid intersect. NaN NaN NaN NaN grain boundary The place where two grains in a solid intersect. NaN NaN NaN NaN greenhouse effect The phenomenon in which substances absorb thermal energy radiated by Earth, thus trapping thermal energy in the atmosphere. NaN NaN NaN NaN greenhouse effect The phenomenon in which substances absorb thermal energy radiated by Earth, thus trapping thermal energy in the atmosphere. NaN NaN NaN NaN greenhouse gases A substance that absorbs thermal energy radiated by Earth, thus trapping thermal energy in the atmosphere. NaN NaN NaN NaN greenhouse gases A substance that absorbs thermal energy radiated by Earth, thus trapping thermal energy in the atmosphere. NaN NaN NaN NaN group-transfer reactions A reaction in which a recognizable functional group is transferred from one molecule to another. NaN NaN NaN NaN group-transfer reactions A reaction in which a recognizable functional group is transferred from one molecule to another. NaN NaN NaN NaN half-life The period of time it takes for the concentration of a reactant to decrease to one-half its initial value. NaN NaN NaN NaN half-life The period of time it takes for the concentration of a reactant to decrease to one-half its initial value. NaN NaN NaN NaN hardness The resistance of ionic materials to scratching or abrasion. NaN NaN NaN NaN hardness The resistance of ionic materials to scratching or abrasion. NaN NaN NaN NaN heat (q) Thermal energy that can be transformed from an object at one temperature to an object at another temperature. NaN NaN NaN NaN heat (q) Thermal energy that can be transformed from an object at one temperature to an object at another temperature. NaN NaN NaN NaN heat capacity (C) The amount of energy needed to raise the temperature of an object 1°C. The units of heat capacity are joules per degree Celsius (J/°C). NaN NaN NaN NaN heat capacity (C) The amount of energy needed to raise the temperature of an object 1°C. The units of heat capacity are joules per degree Celsius (J/°C). NaN NaN NaN NaN Heisenberg uncertainty principle A principle stating that the uncertainty in the position of a particle (Δx) multiplied by the uncertainty in its momentum [Δ(mv)] is greater than or equal to Planck’s constant (h) divided by 4π: Δx[Δ(mv)]≥h/4π. NaN NaN NaN NaN Heisenberg uncertainty principle A principle stating that the uncertainty in the position of a particle (Δx) multiplied by the uncertainty in its momentum [Δ(mv)] is greater than or equal to Planck’s constant (h) divided by 4π: Δx[Δ(mv)]≥h/4π. NaN NaN NaN NaN Henderson-Hasselbalch equation A rearranged version of the equilibrium constant expression that provides a direct way to calculate the pH of a buffer solution: pH = pKa + log([base]/[acid]). NaN NaN NaN NaN Henry’s law An equation that quantifies the relationship between the pressure and the solubility of a gas: C=kP. NaN NaN NaN NaN Henry’s law An equation that quantifies the relationship between the pressure and the solubility of a gas: C=kP. NaN NaN NaN NaN Hess’s law The enthalpy change (ΔH) for an overall reaction is the sum of the ΔH values for the individual reactions. NaN NaN NaN NaN Hess’s law The enthalpy change (ΔH) for an overall reaction is the sum of the ΔH values for the individual reactions. NaN NaN NaN NaN heterogeneous A mixture in which a material is not completely uniform throughout. NaN NaN NaN NaN heterogeneous A mixture in which a material is not completely uniform throughout. NaN NaN NaN NaN heterogeneous catalysis A catalytic reaction in which the catalyst is in a different phase from the reactants. NaN NaN NaN NaN heterogeneous catalysis A catalytic reaction in which the catalyst is in a different phase from the reactants. NaN NaN NaN NaN heterogeneous catalyst A catalyst that is in a different physical state than the reactants. NaN NaN NaN NaN heterogeneous catalyst A catalyst that is in a different physical state than the reactants. NaN NaN NaN NaN heterogeneous equilibrium An equilibrium in which the reactants of an equilibrium reaction, the products, or both are in more than one phase. NaN NaN NaN NaN heterogeneous equilibrium An equilibrium in which the reactants of an equilibrium reaction, the products, or both are in more than one phase. NaN NaN NaN NaN heteronuclear diatomic molecules A molecule that consists of two atoms of different elements. NaN NaN NaN NaN heteronuclear diatomic molecules A molecule that consists of two atoms of different elements. NaN NaN NaN NaN high-temperature superconductors A material that becomes a superconductor at temperatures greater than 30 K. NaN NaN NaN NaN high-temperature superconductors A material that becomes a superconductor at temperatures greater than 30 K. NaN NaN NaN NaN homogeneous A mixture in which all portions of a material are in the same state, have no visible boundaries, and are uniform throughout. NaN NaN NaN NaN homogeneous A mixture in which all portions of a material are in the same state, have no visible boundaries, and are uniform throughout. NaN NaN NaN NaN homogeneous catalysis A catalytic reaction in which the catalyst is uniformly dispersed throughout the reactant mixture to form a solution. NaN NaN NaN NaN homogeneous catalysis A catalytic reaction in which the catalyst is uniformly dispersed throughout the reactant mixture to form a solution. NaN NaN NaN NaN homonuclear diatomic molecule A molecule that consists of two atoms of the same element. NaN NaN NaN NaN homonuclear diatomic molecule A molecule that consists of two atoms of the same element. NaN NaN NaN NaN Hund’s rule A rule stating that the lowest-energy electron configuration for an atom is the one that has the maximum number of electrons with parallel spins in degenerate orbitals. NaN NaN NaN NaN Hund’s rule A rule stating that the lowest-energy electron configuration for an atom is the one that has the maximum number of electrons with parallel spins in degenerate orbitals. NaN NaN NaN NaN hybrid atomic orbitals New atomic orbitals formed from the process of hybridization. NaN NaN NaN NaN hybrid atomic orbitals New atomic orbitals formed from the process of hybridization. NaN NaN NaN NaN hydrated ions Individual cations and anions that are each surrounded by their own shell of water molecules. NaN NaN NaN NaN hydrated ions Individual cations and anions that are each surrounded by their own shell of water molecules. NaN NaN NaN NaN hydration The process of surrounding solute particles with water molecules. NaN NaN NaN NaN hydration The process of surrounding solute particles with water molecules. NaN NaN NaN NaN hydrogen bonds An unusually strong dipole-dipole interaction (intermolecular force) that results when hydrogen is bonded to very electronegative elements, such as O, N, and F. NaN NaN NaN NaN hydrogen bonds An unusually strong dipole-dipole interaction (intermolecular force) that results when hydrogen is bonded to very electronegative elements, such as O, N, and F. NaN NaN NaN NaN hydrolysis reactions A chemical reaction in which a salt reacts with water to yield an acidic or a basic solution. NaN NaN NaN NaN hydronium ion The H3O+ ion, represented as H+(aq). NaN NaN NaN NaN hydronium ion The H3O+ ion, represented as H+(aq). NaN NaN NaN NaN hydrophobic A substance that repels water. Hydrophobic substances do not interact favorably with water. NaN NaN NaN NaN hydrophobic A substance that repels water. Hydrophobic substances do not interact favorably with water. NaN NaN NaN NaN hypothesis A tentative explanation for scientific observations that puts the system being studied into a form that can be tested. NaN NaN NaN NaN hypothesis A tentative explanation for scientific observations that puts the system being studied into a form that can be tested. NaN NaN NaN NaN ideal gas A hypothetical gaseous substance whose behavior is independent of attractive and repulsive forces. NaN NaN NaN NaN ideal gas A hypothetical gaseous substance whose behavior is independent of attractive and repulsive forces. NaN NaN NaN NaN ideal gas law A law relating pressure, temperature, volume, and the amount of an ideal gas. NaN NaN NaN NaN ideal gas law A law relating pressure, temperature, volume, and the amount of an ideal gas. NaN NaN NaN NaN ideal solution A solution that obeys Raoult’s law. NaN NaN NaN NaN ideal solution A solution that obeys Raoult’s law. NaN NaN NaN NaN indicators An intensely colored organic molecule whose color changes dramatically depending on the pH of the solution. NaN NaN NaN NaN indicators An intensely colored organic molecule whose color changes dramatically depending on the pH of the solution. NaN NaN NaN NaN induced dipole A short-lived dipole moment that is created in atoms and nonpolar molecules adjacent to atoms or molecules with an instantaneous dipole moment. NaN NaN NaN NaN induced dipole A short-lived dipole moment that is created in atoms and nonpolar molecules adjacent to atoms or molecules with an instantaneous dipole moment. NaN NaN NaN NaN inert metals The metals at the bottom of the activity series, which have the least tendency to be oxidized. NaN NaN NaN NaN inert metals The metals at the bottom of the activity series, which have the least tendency to be oxidized. NaN NaN NaN NaN inorganic compounds An ionic or covalent compound that consists primarily of elements other than carbon and hydrogen. NaN NaN NaN NaN inorganic compounds An ionic or covalent compound that consists primarily of elements other than carbon and hydrogen. NaN NaN NaN NaN instantaneous rate The reaction rate of a chemical reaction at any given point in time. NaN NaN NaN NaN instantaneous rate The reaction rate of a chemical reaction at any given point in time. NaN NaN NaN NaN integrated rate law A rate law that expresses the reaction rate in terms of the initial concentration ([R0]) and the measured concentration of one or more reactants ([R]) after a given amount of time (t). NaN NaN NaN NaN integrated rate law A rate law that expresses the reaction rate in terms of the initial concentration ([R0]) and the measured concentration of one or more reactants ([R]) after a given amount of time (t). NaN NaN NaN NaN Intensive properties A physical property that does not depend on the amount of the substance and physical state at a given temperature and pressure. NaN NaN NaN NaN Intensive properties A physical property that does not depend on the amount of the substance and physical state at a given temperature and pressure. NaN NaN NaN NaN intermediate A species in a reaction mechanism that does not appear in the balanced chemical equation for the overall reaction. NaN NaN NaN NaN intermediate A species in a reaction mechanism that does not appear in the balanced chemical equation for the overall reaction. NaN NaN NaN NaN intermetallic compounds An alloy that consists of certain metals that combine in only specific proportions and whose properties are frequently quite different from those of their constituent elements. NaN NaN NaN NaN intermetallic compounds An alloy that consists of certain metals that combine in only specific proportions and whose properties are frequently quite different from those of their constituent elements. NaN NaN NaN NaN interstitial alloy An alloy formed by inserting smaller atoms into holes in the metal lattice. NaN NaN NaN NaN interstitial alloy An alloy formed by inserting smaller atoms into holes in the metal lattice. NaN NaN NaN NaN interstitial impurity A point defect that results when an impurity atom occupies an octahedral hole or a tetrahedral hole in the lattice between atoms. NaN NaN NaN NaN interstitial impurity A point defect that results when an impurity atom occupies an octahedral hole or a tetrahedral hole in the lattice between atoms. NaN NaN NaN NaN ion pairs A cation and anion that are in intimate contact in solution rather than separated by solvent and that migrates in solution as a single unit. NaN NaN NaN NaN ion pairs A cation and anion that are in intimate contact in solution rather than separated by solvent and that migrates in solution as a single unit. NaN NaN NaN NaN ion pumps A complex assembly of proteins that selectively transports ions across cell membranes toward the side with the higher concentration. NaN NaN NaN NaN ion pumps A complex assembly of proteins that selectively transports ions across cell membranes toward the side with the higher concentration. NaN NaN NaN NaN ion-product constant of liquid water (Kw) An equilibrium constant for the autoionization of water, 2H2O(l) ⇌ H3O+(aq) + OH−(aq), in which the concentration of water is treated as a constant: Kw = [H3O+][OH−] = 1.006×10−14. NaN NaN NaN NaN ion-product constant of liquid water (Kw) An equilibrium constant for the autoionization of water, 2H2O(l) ⇌ H3O+(aq) + OH−(aq), in which the concentration of water is treated as a constant: Kw = [H3O+][OH−] = 1.006×10−14. NaN NaN NaN NaN ionic bonding A type of chemical bonding in which positively and negatively charged ions are held together by electrostatic forces. NaN NaN NaN NaN ionic bonding A type of chemical bonding in which positively and negatively charged ions are held together by electrostatic forces. NaN NaN NaN NaN ionic liquids Ionic substances that are liquids at room temperature and pressure and that consist of small, symmetrical anions combined with larger, symmetrical organic cations that prevent the formation of a highly organized structure. NaN NaN NaN NaN ionic liquids Ionic substances that are liquids at room temperature and pressure and that consist of small, symmetrical anions combined with larger, symmetrical organic cations that prevent the formation of a highly organized structure. NaN NaN NaN NaN ionic radius The radius of a cation or anion. NaN NaN NaN NaN ionic radius The radius of a cation or anion. NaN NaN NaN NaN ionic solid A solid that consists of positively and negatively charged ions held together by electrostatic forces. NaN NaN NaN NaN ionic solid A solid that consists of positively and negatively charged ions held together by electrostatic forces. NaN NaN NaN NaN ionization energy(I) The minimum amount of energy needed to remove an electron from the gaseous atom in its ground state: E(g) + I→E+(g)+e−. NaN NaN NaN NaN ionization energy(I) The minimum amount of energy needed to remove an electron from the gaseous atom in its ground state: E(g) + I→E+(g)+e−. NaN NaN NaN NaN ions A charged particle produced when one or more electrons is removed from or added to an atom or molecule. NaN NaN NaN NaN ions A charged particle produced when one or more electrons is removed from or added to an atom or molecule. NaN NaN NaN NaN isoelectronic series A group of ions or atoms and ions that have the same number of electrons and thus the same ground-state electron configuration. NaN NaN NaN NaN isoelectronic series A group of ions or atoms and ions that have the same number of electrons and thus the same ground-state electron configuration. NaN NaN NaN NaN isolated system A system that can exchange neither energy nor matter with its suroundings. NaN NaN NaN NaN isolated system A system that can exchange neither energy nor matter with its suroundings. NaN NaN NaN NaN joule (J) The SI unit of energy: 1 J = 1 kg•m2/s2. NaN NaN NaN NaN joule (J) The SI unit of energy: 1 J = 1 kg•m2/s2. NaN NaN NaN NaN ketones A class of organic compounds with the general form RC(O)R’, in which the carbon atom of the carbonyl group is bonded to two alkyl groups (c.f. aldehyde). The alkyl groups may be the same or different. NaN NaN NaN NaN ketones A class of organic compounds with the general form RC(O)R’, in which the carbon atom of the carbonyl group is bonded to two alkyl groups (c.f. aldehyde). The alkyl groups may be the same or different. NaN NaN NaN NaN kinetic energy (KE) Energy due to the motion of an object: KE=12mv2, where m is the mass of the object and v is its velocity. NaN NaN NaN NaN kinetic energy (KE) Energy due to the motion of an object: KE=12mv2, where m is the mass of the object and v is its velocity. NaN NaN NaN NaN kinetic molecular theory of gases A theory that describes, on the molecular level, why ideal gases behave the way they do. NaN NaN NaN NaN kinetic molecular theory of gases A theory that describes, on the molecular level, why ideal gases behave the way they do. NaN NaN NaN NaN Kp An equilibrium constant expressed as the ratio of the partial pressures of the products and reactants, each raised to its coefficient in the chemical equation. NaN NaN NaN NaN Kp An equilibrium constant expressed as the ratio of the partial pressures of the products and reactants, each raised to its coefficient in the chemical equation. NaN NaN NaN NaN law of conservation of energy The total amount of energy in the universe remains constant. Energy can be neither created nor destroyed, but it can be converted from one form to another. NaN NaN NaN NaN law of conservation of energy The total amount of energy in the universe remains constant. Energy can be neither created nor destroyed, but it can be converted from one form to another. NaN NaN NaN NaN law of conservation of mass In any chemical reaction, the mass of the substances that react equals the mass of the products that are formed. NaN NaN NaN NaN law of conservation of mass In any chemical reaction, the mass of the substances that react equals the mass of the products that are formed. NaN NaN NaN NaN law of conservation of orbitals A law that states that the number of molecular orbitals produced is the same as the number of atomic orbitals used to create them. NaN NaN NaN NaN law of conservation of orbitals A law that states that the number of molecular orbitals produced is the same as the number of atomic orbitals used to create them. NaN NaN NaN NaN law of definite proportions A chemical substance always contains the same proportions of elements by mass. NaN NaN NaN NaN law of definite proportions A chemical substance always contains the same proportions of elements by mass. NaN NaN NaN NaN law of mass action For the general balanced chemical equation aA+bB⇌cC+dD, the equilibrium constant expression is K=[C]c[D]d/[A]a[B]b. NaN NaN NaN NaN law of mass action For the general balanced chemical equation aA+bB⇌cC+dD, the equilibrium constant expression is K=[C]c[D]d/[A]a[B]b. NaN NaN NaN NaN law of multiple proportions When two elements form a series of compounds, the ratios of the masses of the second element that are present per gram of the first element can almost always be expressed as the ratios of integers. (The same law holds for the mass ratios of compounds forming a series that contains more than two elements.) NaN NaN NaN NaN law of multiple proportions When two elements form a series of compounds, the ratios of the masses of the second element that are present per gram of the first element can almost always be expressed as the ratios of integers. (The same law holds for the mass ratios of compounds forming a series that contains more than two elements.) NaN NaN NaN NaN Le Châtelier’s principle If a stress is applied to a system at equilibrium, the composition of the system will change to relieve the applied stress. NaN NaN NaN NaN Le Châtelier’s principle If a stress is applied to a system at equilibrium, the composition of the system will change to relieve the applied stress. NaN NaN NaN NaN leveling effect The phenomenon that makes H3O+ the strongest acid that can exist in water. Any species that is a stronger acid than H3O+ is leveled to the strength of H3O+ in aqueous solution. NaN NaN NaN NaN Lewis acid Any species that can accept a pair of electrons. NaN NaN NaN NaN Lewis acid Any species that can accept a pair of electrons. NaN NaN NaN NaN Lewis electron dot symbols A system that can be used to predict the number of bonds formed by most elements in their compounds. NaN NaN NaN NaN Lewis electron dot symbols A system that can be used to predict the number of bonds formed by most elements in their compounds. NaN NaN NaN NaN limiting reactant The reactant that restricts the amount of product obtained in a chemical reaction. NaN NaN NaN NaN limiting reactant The reactant that restricts the amount of product obtained in a chemical reaction. NaN NaN NaN NaN line spectrum A spectrum in which light of only a certain wavelength is emitted or absorbed, rather than a continuous range of wavelengths. NaN NaN NaN NaN line spectrum A spectrum in which light of only a certain wavelength is emitted or absorbed, rather than a continuous range of wavelengths. NaN NaN NaN NaN linear combinations of atomic orbitals (LCAOs) Molecular orbitals created from the sum and the difference of two wave functions (atomic orbitals). NaN NaN NaN NaN linear combinations of atomic orbitals (LCAOs) Molecular orbitals created from the sum and the difference of two wave functions (atomic orbitals). NaN NaN NaN NaN Liquefaction The condensation of gases into a liquid form. NaN NaN NaN NaN Liquefaction The condensation of gases into a liquid form. NaN NaN NaN NaN liquid crystals A substance that exhibits phases that have properties intermediate between those of a crystalline solid and a normal liquid and possess long-range molecular order but still flow. NaN NaN NaN NaN liquid crystals A substance that exhibits phases that have properties intermediate between those of a crystalline solid and a normal liquid and possess long-range molecular order but still flow. NaN NaN NaN NaN London dispersion forces A kind of intermolecular interaction (force) that results from temporary fluctuations in the electron distribution within atoms and nonpolar molecules. NaN NaN NaN NaN London dispersion forces A kind of intermolecular interaction (force) that results from temporary fluctuations in the electron distribution within atoms and nonpolar molecules. NaN NaN NaN NaN lustrous Having a shiny appearance. Metals are lustrous, whereas nonmetals are not. NaN NaN NaN NaN lustrous Having a shiny appearance. Metals are lustrous, whereas nonmetals are not. NaN NaN NaN NaN macrominerals Any of the six essential elements (Na, Mg, K, Ca, Cl, and P) that provide essential ions in body fluids and form the major structural components of the body. NaN NaN NaN NaN macrominerals Any of the six essential elements (Na, Mg, K, Ca, Cl, and P) that provide essential ions in body fluids and form the major structural components of the body. NaN NaN NaN NaN magnetic quantum number (ml) One of three quantum numbers that describes the orientation of the region of space occupied by an electron with respect to an applied magnetic field. NaN NaN NaN NaN magnetic quantum number (ml) One of three quantum numbers that describes the orientation of the region of space occupied by an electron with respect to an applied magnetic field. NaN NaN NaN NaN manometers A device used to measure the pressures of samples of gases contained in an apparatus. NaN NaN NaN NaN manometers A device used to measure the pressures of samples of gases contained in an apparatus. NaN NaN NaN NaN mass number (A) The number of protons and neutrons in the nucleus of an atom of an element. NaN NaN NaN NaN mass number (A) The number of protons and neutrons in the nucleus of an atom of an element. NaN NaN NaN NaN matter Anything that occupies space and has mass. NaN NaN NaN NaN matter Anything that occupies space and has mass. NaN NaN NaN NaN mean free path The average distance traveled by a molecule between collisions. NaN NaN NaN NaN mean free path The average distance traveled by a molecule between collisions. NaN NaN NaN NaN mechanical work The energy required to move an object a distance d when opposed by a force F: w=F×d. NaN NaN NaN NaN mechanical work The energy required to move an object a distance d when opposed by a force F: w=F×d. NaN NaN NaN NaN Meissner effect The phenomenon in which a superconductor completely expels a magnetic field from its interior. NaN NaN NaN NaN Meissner effect The phenomenon in which a superconductor completely expels a magnetic field from its interior. NaN NaN NaN NaN melting point The temperature at which the individual ions in a lattice or the individual molecules in a covalent compound have enough kinetic energy to overcome the attractive forces that hold them together in the solid. NaN NaN NaN NaN melting point The temperature at which the individual ions in a lattice or the individual molecules in a covalent compound have enough kinetic energy to overcome the attractive forces that hold them together in the solid. NaN NaN NaN NaN meniscus The upper surface of the liquid in a tube. NaN NaN NaN NaN meniscus The upper surface of the liquid in a tube. NaN NaN NaN NaN Metal-matrix composites A composite that consists of reinforcing fibers embedded in a metal or a metal alloy matrix. NaN NaN NaN NaN Metal-matrix composites A composite that consists of reinforcing fibers embedded in a metal or a metal alloy matrix. NaN NaN NaN NaN metallic solids A solid that consists of metal atoms held together by metallic bonds. NaN NaN NaN NaN metallic solids A solid that consists of metal atoms held together by metallic bonds. NaN NaN NaN NaN micelles A spherical or cylindrical aggregate of detergents or soaps in water that minimizes contact between the hydrophobic tails of the detergents or soaps and water. NaN NaN NaN NaN micelles A spherical or cylindrical aggregate of detergents or soaps in water that minimizes contact between the hydrophobic tails of the detergents or soaps and water. NaN NaN NaN NaN midpoint The point in an acid–base titration at which exactly enough acid (or base) has been added to neutralize one-half of the base (or the acid) originally present: [HA]=[A−]. NaN NaN NaN NaN miscible Capable of forming a single homogeneous phase, regardless of the proportions with which the substances are mixed. NaN NaN NaN NaN miscible Capable of forming a single homogeneous phase, regardless of the proportions with which the substances are mixed. NaN NaN NaN NaN molality (m) The number of moles of solute present in exactly 1 kg of solvent. NaN NaN NaN NaN molality (m) The number of moles of solute present in exactly 1 kg of solvent. NaN NaN NaN NaN molar mass The mass in grams of 1 mol of a substance. NaN NaN NaN NaN molar mass The mass in grams of 1 mol of a substance. NaN NaN NaN NaN molar volume The molar mass of an element divided by its density. NaN NaN NaN NaN molar volume The molar mass of an element divided by its density. NaN NaN NaN NaN molarity (M) A common unit of concentration that is the number of moles of solute present in exactly 1 L of solution (mol/L). NaN NaN NaN NaN molarity (M) A common unit of concentration that is the number of moles of solute present in exactly 1 L of solution (mol/L). NaN NaN NaN NaN mole (mol) The quantity of a substance that contains the same number of units (e.g., atoms or molecules) as the number of carbon atoms in exactly 12 g of isotopically pure carbon-12. NaN NaN NaN NaN mole (mol) The quantity of a substance that contains the same number of units (e.g., atoms or molecules) as the number of carbon atoms in exactly 12 g of isotopically pure carbon-12. NaN NaN NaN NaN mole fraction (X) The ratio of the number of moles of any component of a mixture to the total number of moles of all species present in the mixture. NaN NaN NaN NaN mole fraction (X) The ratio of the number of moles of any component of a mixture to the total number of moles of all species present in the mixture. NaN NaN NaN NaN mole ratio The ratio of the number of moles of one substance to the number of moles of another, as depicted by a balanced chemical equation. NaN NaN NaN NaN mole ratio The ratio of the number of moles of one substance to the number of moles of another, as depicted by a balanced chemical equation. NaN NaN NaN NaN molecular formula A representation of a covalent compound that consists of the atomic symbol for each component element (in a prescribed order) accompanied by a subscript indicating the number of atoms of that element in the molecule. The subscript is written only if the number is greater than 1. NaN NaN NaN NaN molecular formula A representation of a covalent compound that consists of the atomic symbol for each component element (in a prescribed order) accompanied by a subscript indicating the number of atoms of that element in the molecule. The subscript is written only if the number is greater than 1. NaN NaN NaN NaN molecular geometry The arrangement of the bonded atoms in a molecule or a polyatomic ion in space. NaN NaN NaN NaN molecular geometry The arrangement of the bonded atoms in a molecule or a polyatomic ion in space. NaN NaN NaN NaN molecular mass The sum of the average masses of the atoms in one molecule of a substance, each multiplied by its subscript. NaN NaN NaN NaN molecular mass The sum of the average masses of the atoms in one molecule of a substance, each multiplied by its subscript. NaN NaN NaN NaN molecular orbital theory A delocalized bonding model in which molecular orbitals are created from the linear combination of atomic orbitals (LCAOs). NaN NaN NaN NaN molecular orbital theory A delocalized bonding model in which molecular orbitals are created from the linear combination of atomic orbitals (LCAOs). NaN NaN NaN NaN Molecular solids A solid that consists of molecules held together by relatively weak forces, such as dipole-dipole interactions, hydrogen bonds, and London dispersion forces. NaN NaN NaN NaN Molecular solids A solid that consists of molecules held together by relatively weak forces, such as dipole-dipole interactions, hydrogen bonds, and London dispersion forces. NaN NaN NaN NaN molecularity The number of molecules that collide during any step in a reaction mechanism. NaN NaN NaN NaN molecularity The number of molecules that collide during any step in a reaction mechanism. NaN NaN NaN NaN molten salt A salt that has been heated to its melting point. NaN NaN NaN NaN molten salt A salt that has been heated to its melting point. NaN NaN NaN NaN monatomic A species containing a single atom. NaN NaN NaN NaN monatomic A species containing a single atom. NaN NaN NaN NaN monatomic ions An ion with only a single atom. NaN NaN NaN NaN monatomic ions An ion with only a single atom. NaN NaN NaN NaN n-type semiconductor A semiconductor that has been doped with an impurity that has more valence electrons than the atoms of the host lattice. NaN NaN NaN NaN n-type semiconductor A semiconductor that has been doped with an impurity that has more valence electrons than the atoms of the host lattice. NaN NaN NaN NaN nanotubes One of at least four allotropes of carbon that are cylinders of carbon atoms and are intermediate in structure between graphite and the fullerenes. NaN NaN NaN NaN nanotubes One of at least four allotropes of carbon that are cylinders of carbon atoms and are intermediate in structure between graphite and the fullerenes. NaN NaN NaN NaN net ionic equation A chemical equation that shows only those species that participate in the chemical reaction. NaN NaN NaN NaN net ionic equation A chemical equation that shows only those species that participate in the chemical reaction. NaN NaN NaN NaN neutral solution A solution in which the total positive charge from all the cations is matched by an identical total negative charge from all the anions. NaN NaN NaN NaN neutral solution A solution in which the total positive charge from all the cations is matched by an identical total negative charge from all the anions. NaN NaN NaN NaN neutrons A subatomic particle with no charge that resides in the nucleus of almost all atoms. NaN NaN NaN NaN neutrons A subatomic particle with no charge that resides in the nucleus of almost all atoms. NaN NaN NaN NaN noble gases Any element in group 18 of the periodic table. All are unreactive monatomic gases at room temperature and pressure. NaN NaN NaN NaN noble gases Any element in group 18 of the periodic table. All are unreactive monatomic gases at room temperature and pressure. NaN NaN NaN NaN nodes The point where the amplitude of a wave is zero. NaN NaN NaN NaN nodes The point where the amplitude of a wave is zero. NaN NaN NaN NaN nonbonding molecular orbitals A molecular orbital that forms when atomic orbitals or orbital lobes interact only very weakly, creating essentially no change in the electron probability density between the nuclei. NaN NaN NaN NaN nonbonding molecular orbitals A molecular orbital that forms when atomic orbitals or orbital lobes interact only very weakly, creating essentially no change in the electron probability density between the nuclei. NaN NaN NaN NaN nonstoichiometric compounds A solid that has intrinsically variable stoichiometries without affecting the fundamental structure of the crystal. NaN NaN NaN NaN nonstoichiometric compounds A solid that has intrinsically variable stoichiometries without affecting the fundamental structure of the crystal. NaN NaN NaN NaN nonvolatile liquids A liquid with a relatively low vapor pressure. NaN NaN NaN NaN nonvolatile liquids A liquid with a relatively low vapor pressure. NaN NaN NaN NaN normal boiling point The temperature at which a substance boils at a pressure of 1 atm. NaN NaN NaN NaN normal boiling point The temperature at which a substance boils at a pressure of 1 atm. NaN NaN NaN NaN nucleus The central core of an atom where protons and any neutrons reside. NaN NaN NaN NaN nucleus The central core of an atom where protons and any neutrons reside. NaN NaN NaN NaN octane rating A measure of a fuel’s ability to burn in a combustion engine without knocking or pinging (indications of premature combustion). The higher the octane rating, the higher quality the fuel. NaN NaN NaN NaN octane rating A measure of a fuel’s ability to burn in a combustion engine without knocking or pinging (indications of premature combustion). The higher the octane rating, the higher quality the fuel. NaN NaN NaN NaN octaves A group of seven elements, corresponding to the horizontal rows in the main group elements (not counting the noble gases, which were unknown at the time). NaN NaN NaN NaN octaves A group of seven elements, corresponding to the horizontal rows in the main group elements (not counting the noble gases, which were unknown at the time). NaN NaN NaN NaN octet rule The tendency for atoms to lose, gain, or share electrons to reach a total of eight valence electrons. NaN NaN NaN NaN octet rule The tendency for atoms to lose, gain, or share electrons to reach a total of eight valence electrons. NaN NaN NaN NaN orbital energies A particular energy associated with a given set of quantum numbers. NaN NaN NaN NaN orbital energies A particular energy associated with a given set of quantum numbers. NaN NaN NaN NaN osmosis The net flow of solvent through a semipermeable membrane. NaN NaN NaN NaN osmosis The net flow of solvent through a semipermeable membrane. NaN NaN NaN NaN osmotic pressure (Π) The pressure difference between the two sides of a semipermeable membrane that separates a pure solvent from a solution prepared from the same solvent. NaN NaN NaN NaN osmotic pressure (Π) The pressure difference between the two sides of a semipermeable membrane that separates a pure solvent from a solution prepared from the same solvent. NaN NaN NaN NaN overall chemical equation A chemical equation that shows all the reactants and products as undissociated, electrically neutral compounds. NaN NaN NaN NaN overall chemical equation A chemical equation that shows all the reactants and products as undissociated, electrically neutral compounds. NaN NaN NaN NaN overlapping bands Molecular orbitals derived from two or more different kinds of valence electrons that have similar energies. NaN NaN NaN NaN overlapping bands Molecular orbitals derived from two or more different kinds of valence electrons that have similar energies. NaN NaN NaN NaN overtones The vibration of a standing wave that is higher in energy than the fundamental vibration. NaN NaN NaN NaN overtones The vibration of a standing wave that is higher in energy than the fundamental vibration. NaN NaN NaN NaN oxidation The loss of one or more electrons in a chemical reaction. The substance that loses electrons is said to be oxidized. NaN NaN NaN NaN oxidation The loss of one or more electrons in a chemical reaction. The substance that loses electrons is said to be oxidized. NaN NaN NaN NaN oxidation state The charge that each atom in a compound would have if all its bonding electrons were transferred to the atom with the greater attraction for electrons. NaN NaN NaN NaN oxidation state The charge that each atom in a compound would have if all its bonding electrons were transferred to the atom with the greater attraction for electrons. NaN NaN NaN NaN oxidation state method A procedure for balancing oxidation–reduction (redox) reactions in which the overall reaction is conceptually separated into two parts: an oxidation and a reduction. NaN NaN NaN NaN oxidation state method A procedure for balancing oxidation–reduction (redox) reactions in which the overall reaction is conceptually separated into two parts: an oxidation and a reduction. NaN NaN NaN NaN oxidation–reduction reactions A chemical reaction that exhibits a change in the oxidation states of one or more elements in the reactants that has the general form oxidant + reductant → reduced oxidant + oxidized reductant. NaN NaN NaN NaN oxidation–reduction reactions A chemical reaction that exhibits a change in the oxidation states of one or more elements in the reactants that has the general form oxidant + reductant → reduced oxidant + oxidized reductant. NaN NaN NaN NaN oxoacids An acid in which the dissociable H+ ion is attached to an oxygen atom of a polyatomic anion. NaN NaN NaN NaN oxoacids An acid in which the dissociable H+ ion is attached to an oxygen atom of a polyatomic anion. NaN NaN NaN NaN Ozone An unstable form of oxygen that consists of three oxygen atoms bonded together (O3). A layer of ozone in the stratosphere helps protect the plants and animals on earth from harmful ultraviolet radiation. Ozone is responsible for the pungent smell we associate with lightning discharges and electric motors. It is also toxic. NaN NaN NaN NaN Ozone An unstable form of oxygen that consists of three oxygen atoms bonded together (O3). A layer of ozone in the stratosphere helps protect the plants and animals on earth from harmful ultraviolet radiation. Ozone is responsible for the pungent smell we associate with lightning discharges and electric motors. It is also toxic. NaN NaN NaN NaN ozone layer A concentration of ozone in the stratosphere (about 1015 ozone molecules per liter) that acts as a protective screen, absorbing ultraviolet light that would otherwise reach the surface of the earth, where it would harm plants and animals. NaN NaN NaN NaN ozone layer A concentration of ozone in the stratosphere (about 1015 ozone molecules per liter) that acts as a protective screen, absorbing ultraviolet light that would otherwise reach the surface of the earth, where it would harm plants and animals. NaN NaN NaN NaN p-type semiconductor A semiconductor that has been doped with an impurity that has fewer valence electrons than the atoms of the host lattice. NaN NaN NaN NaN p-type semiconductor A semiconductor that has been doped with an impurity that has fewer valence electrons than the atoms of the host lattice. NaN NaN NaN NaN partial pressure The pressure a gas in a mixture would exert if it were the only one present (at the same temperature and volume). NaN NaN NaN NaN partial pressure The pressure a gas in a mixture would exert if it were the only one present (at the same temperature and volume). NaN NaN NaN NaN parts per billion (ppb) Micrograms of solute per kilogram of solvent. NaN NaN NaN NaN parts per billion (ppb) Micrograms of solute per kilogram of solvent. NaN NaN NaN NaN parts per thousand (ppt) Grams of solute per kilogram of solvent, primarily used in the health sciences. NaN NaN NaN NaN parts per thousand (ppt) Grams of solute per kilogram of solvent, primarily used in the health sciences. NaN NaN NaN NaN pascal (Pa) The SI unit for pressure. The pascal is newtons per square meter: N/m2. NaN NaN NaN NaN pascal (Pa) The SI unit for pressure. The pascal is newtons per square meter: N/m2. NaN NaN NaN NaN Pauli exclusion principle A principle stating that no two electrons in an atom can have the same value of all four quantum numbers. NaN NaN NaN NaN Pauli exclusion principle A principle stating that no two electrons in an atom can have the same value of all four quantum numbers. NaN NaN NaN NaN percent composition The percentage of each element present in a pure substance. With few exceptions, the percent composition of a chemical compound is constant (see law of definite proportions). NaN NaN NaN NaN percent composition The percentage of each element present in a pure substance. With few exceptions, the percent composition of a chemical compound is constant (see law of definite proportions). NaN NaN NaN NaN percent yield The ratio of the actual yield of a reaction to the theoretical yield multiplied by 100 to give a percentage. NaN NaN NaN NaN percent yield The ratio of the actual yield of a reaction to the theoretical yield multiplied by 100 to give a percentage. NaN NaN NaN NaN periodic table A chart of the chemical elements arranged in rows of increasing atomic number so that the elements in each column (group) have similar chemical properties. NaN NaN NaN NaN periodic table A chart of the chemical elements arranged in rows of increasing atomic number so that the elements in each column (group) have similar chemical properties. NaN NaN NaN NaN perovskite structure A structure that consists of a bcc array of two metal ions, with one set (M) located at the corners of the cube, and the other set (M′) in the centers of the cube. NaN NaN NaN NaN perovskite structure A structure that consists of a bcc array of two metal ions, with one set (M) located at the corners of the cube, and the other set (M′) in the centers of the cube. NaN NaN NaN NaN pH The negative base-10 logarithm of the hydrogen ion concentration: pH =−log[H+]. NaN NaN NaN NaN pH The negative base-10 logarithm of the hydrogen ion concentration: pH =−log[H+]. NaN NaN NaN NaN pH scale A logarithmic scale used to express the hydrogen ion (H+) concentration of a solution, making it possible to describe acidity or basicity quantitatively. NaN NaN NaN NaN pH scale A logarithmic scale used to express the hydrogen ion (H+) concentration of a solution, making it possible to describe acidity or basicity quantitatively. NaN NaN NaN NaN phase changes A change of state that occurs when any of the three forms of matter (solids, liquids, and gases) is converted to either of the other two. NaN NaN NaN NaN phase changes A change of state that occurs when any of the three forms of matter (solids, liquids, and gases) is converted to either of the other two. NaN NaN NaN NaN phase diagram A graphic summary of the physical state of a substance as a function of temperature and pressure in a closed system. NaN NaN NaN NaN phase diagram A graphic summary of the physical state of a substance as a function of temperature and pressure in a closed system. NaN NaN NaN NaN photoelectric effect A phenomenon in which electrons are ejected from the surface of a metal that has been exposed to light. NaN NaN NaN NaN photoelectric effect A phenomenon in which electrons are ejected from the surface of a metal that has been exposed to light. NaN NaN NaN NaN photons A quantum of radiant energy, each of which possesses a particular energy E given by E=hν. NaN NaN NaN NaN photons A quantum of radiant energy, each of which possesses a particular energy E given by E=hν. NaN NaN NaN NaN physical change A change of state that does not affect the chemical composition of a substance. NaN NaN NaN NaN physical change A change of state that does not affect the chemical composition of a substance. NaN NaN NaN NaN pi star (π*) orbital An antibonding molecular orbital formed from the difference of the side-to-side interactions of two or more parallel np atomic orbitals, creating a nodal plane perpendicular to the internuclear axis. NaN NaN NaN NaN pi star (π*) orbital An antibonding molecular orbital formed from the difference of the side-to-side interactions of two or more parallel np atomic orbitals, creating a nodal plane perpendicular to the internuclear axis. NaN NaN NaN NaN pinning A process that increases the mechanical strength of a material by introducing multiple defects into a material so that the presence of one defect prevents the motion of another. NaN NaN NaN NaN pinning A process that increases the mechanical strength of a material by introducing multiple defects into a material so that the presence of one defect prevents the motion of another. NaN NaN NaN NaN Plastic The property of a material that allows it to be molded into almost any shape. NaN NaN NaN NaN Plastic The property of a material that allows it to be molded into almost any shape. NaN NaN NaN NaN pnicogens The elements in group 15 of the periodic table. NaN NaN NaN NaN pnicogens The elements in group 15 of the periodic table. NaN NaN NaN NaN polar bond A chemical bond in which there is an unequal distribution of charge between the bonding atoms. NaN NaN NaN NaN polar bond A chemical bond in which there is an unequal distribution of charge between the bonding atoms. NaN NaN NaN NaN polar covalent bonds A covalent bond in which the electrons are shared unequally between the bonded atoms. NaN NaN NaN NaN polar covalent bonds A covalent bond in which the electrons are shared unequally between the bonded atoms. NaN NaN NaN NaN polarizability The ease of deformation of the electron distribution in an atom or molecule. NaN NaN NaN NaN polarizability The ease of deformation of the electron distribution in an atom or molecule. NaN NaN NaN NaN polyatomic Molecules that contain more than two atoms. NaN NaN NaN NaN polyatomic Molecules that contain more than two atoms. NaN NaN NaN NaN Polyatomic ions A group of two or more atoms that has a net electrical charge. NaN NaN NaN NaN Polyatomic ions A group of two or more atoms that has a net electrical charge. NaN NaN NaN NaN polymer-matrix composite A compositie that consists of reinforcing fibers embedded in a polymer matrix. NaN NaN NaN NaN polymer-matrix composite A compositie that consists of reinforcing fibers embedded in a polymer matrix. NaN NaN NaN NaN precipitate The insoluble product that forms in a precipitation reaction. NaN NaN NaN NaN precipitate The insoluble product that forms in a precipitation reaction. NaN NaN NaN NaN precise Multiple measurements give nearly identical values. NaN NaN NaN NaN precise Multiple measurements give nearly identical values. NaN NaN NaN NaN pressure(P) The amount of force (F) exerted on a given area (A) of surface: P=F/A. NaN NaN NaN NaN pressure(P) The amount of force (F) exerted on a given area (A) of surface: P=F/A. NaN NaN NaN NaN principal quantum number (n) One of three quantum numbers that tells the average relative distance of an electron from the nucleus. NaN NaN NaN NaN principal quantum number (n) One of three quantum numbers that tells the average relative distance of an electron from the nucleus. NaN NaN NaN NaN principal shell All the wave functions that have the same value of n because those electrons have similar average distances from the nucleus. NaN NaN NaN NaN principal shell All the wave functions that have the same value of n because those electrons have similar average distances from the nucleus. NaN NaN NaN NaN product(s) The final compound(s) produced in a chemical reaction. NaN NaN NaN NaN product(s) The final compound(s) produced in a chemical reaction. NaN NaN NaN NaN promotion The excitation of an electron from a filled ns2 atomic orbital to an empty np or (n−1)d valence orbital. NaN NaN NaN NaN promotion The excitation of an electron from a filled ns2 atomic orbital to an empty np or (n−1)d valence orbital. NaN NaN NaN NaN pseudo noble gas configurations The (n−1)d10 and similar electron configurations that are particularly stable and are often encountered in the heavier p-block elements. NaN NaN NaN NaN pseudo noble gas configurations The (n−1)d10 and similar electron configurations that are particularly stable and are often encountered in the heavier p-block elements. NaN NaN NaN NaN pyrolysis A high-temperature decomposition reaction that can be used to form fibers of synthetic polymers. NaN NaN NaN NaN pyrolysis A high-temperature decomposition reaction that can be used to form fibers of synthetic polymers. NaN NaN NaN NaN quantum The smallest possible unit of energy. Energy can be gained or lost only in integral multiples of a quantum. NaN NaN NaN NaN quantum The smallest possible unit of energy. Energy can be gained or lost only in integral multiples of a quantum. NaN NaN NaN NaN quantum mechanics A theory developed by Erwin Schrödinger that describes the energies and spatial distributions of electrons in atoms and molecules. NaN NaN NaN NaN quantum mechanics A theory developed by Erwin Schrödinger that describes the energies and spatial distributions of electrons in atoms and molecules. NaN NaN NaN NaN R The abbreviation used for alkyl groups and aryl groups in general formulas and structures. NaN NaN NaN NaN R The abbreviation used for alkyl groups and aryl groups in general formulas and structures. NaN NaN NaN NaN radicals Species that have one or more unpaired valence electrons. NaN NaN NaN NaN radicals Species that have one or more unpaired valence electrons. NaN NaN NaN NaN radioactivity The spontaneous emission of energy rays (radiation) by matter. NaN NaN NaN NaN radioactivity The spontaneous emission of energy rays (radiation) by matter. NaN NaN NaN NaN Raoult’s law An equation that quantifies the relationship between solution composition and vapor pressure: PA=XAPA0. NaN NaN NaN NaN Raoult’s law An equation that quantifies the relationship between solution composition and vapor pressure: PA=XAPA0. NaN NaN NaN NaN rate constant A proportionality constant whose value is characteristic of the reaction and the reaction conditions and whose numerical value does not change as the reaction progresses under a given set of conditions. NaN NaN NaN NaN rate constant A proportionality constant whose value is characteristic of the reaction and the reaction conditions and whose numerical value does not change as the reaction progresses under a given set of conditions. NaN NaN NaN NaN rate laws Mathematical expressions that describe the relationships between reactant rates and reactant concentrations in a chemical reaction. NaN NaN NaN NaN rate laws Mathematical expressions that describe the relationships between reactant rates and reactant concentrations in a chemical reaction. NaN NaN NaN NaN rate-determining step The slowest step in a reaction mechanism. NaN NaN NaN NaN rate-determining step The slowest step in a reaction mechanism. NaN NaN NaN NaN reaction mechanisms The sequence of events that occur at the molecular level during a reaction. NaN NaN NaN NaN reaction mechanisms The sequence of events that occur at the molecular level during a reaction. NaN NaN NaN NaN reaction order Numbers that indicate the degree to which the reaction rate depends on the concentration of each reactant. NaN NaN NaN NaN reaction order Numbers that indicate the degree to which the reaction rate depends on the concentration of each reactant. NaN NaN NaN NaN reaction quotient (Q) A quantity derived from a set of values measured at any time during the reaction of any mixture of reactants and products, regardless of whether the system is at equilibrium: Q=[C]c[D]d/[A]a[B]b for the general balanced chemical equation aA+bB⇌cC+dD. NaN NaN NaN NaN reaction quotient (Q) A quantity derived from a set of values measured at any time during the reaction of any mixture of reactants and products, regardless of whether the system is at equilibrium: Q=[C]c[D]d/[A]a[B]b for the general balanced chemical equation aA+bB⇌cC+dD. NaN NaN NaN NaN reaction quotient (Qp) A quantity derived from a set of values measured at any time during the reaction of any mixture of reactants and products in the gas phase, regardless of whether the system is at equilibrium: Qp=(PC)c(PD)d/(PA)a(PB)b for the general balanced chemical equation aA+bB⇌cC+dD. NaN NaN NaN NaN reaction quotient (Qp) A quantity derived from a set of values measured at any time during the reaction of any mixture of reactants and products in the gas phase, regardless of whether the system is at equilibrium: Qp=(PC)c(PD)d/(PA)a(PB)b for the general balanced chemical equation aA+bB⇌cC+dD. NaN NaN NaN NaN reaction rates The changes in concentrations of reactants and products with time. NaN NaN NaN NaN reaction rates The changes in concentrations of reactants and products with time. NaN NaN NaN NaN reductants (or reducing agents) A compound that is capable of donating electrons; thus it is oxidized. NaN NaN NaN NaN reductants (or reducing agents) A compound that is capable of donating electrons; thus it is oxidized. NaN NaN NaN NaN reduction The gain of one or more electrons in a chemical reaction. The substance that gains electrons is said to be reduced. NaN NaN NaN NaN reduction The gain of one or more electrons in a chemical reaction. The substance that gains electrons is said to be reduced. NaN NaN NaN NaN reforming The second process used in petroleum refining, which is the chemical conversion of straight-chain alkanes to either branched-chain alkanes or mixtures of aromatic hydrocarbons. NaN NaN NaN NaN reforming The second process used in petroleum refining, which is the chemical conversion of straight-chain alkanes to either branched-chain alkanes or mixtures of aromatic hydrocarbons. NaN NaN NaN NaN resonance structures A Lewis electron structure that has different arrangements of electrons around atoms whose positions do not change. NaN NaN NaN NaN resonance structures A Lewis electron structure that has different arrangements of electrons around atoms whose positions do not change. NaN NaN NaN NaN reverse osmosis A process that uses the application of an external pressure greater than the osmotic pressure of a solution to reverse the flow of solvent through the semipermeable membrane. NaN NaN NaN NaN reverse osmosis A process that uses the application of an external pressure greater than the osmotic pressure of a solution to reverse the flow of solvent through the semipermeable membrane. NaN NaN NaN NaN root mean square (rms) speed(vrms) The speed of a gas particle that has average kinetic energy. NaN NaN NaN NaN root mean square (rms) speed(vrms) The speed of a gas particle that has average kinetic energy. NaN NaN NaN NaN salt The general term for any ionic substance that does not have OH− as the anion or H+ as the cation. NaN NaN NaN NaN salt The general term for any ionic substance that does not have OH− as the anion or H+ as the cation. NaN NaN NaN NaN saturated A solution with the maximum possible amount of a solute under a given set of conditions. NaN NaN NaN NaN saturated A solution with the maximum possible amount of a solute under a given set of conditions. NaN NaN NaN NaN Schottky defects A coupled pair of vacancies—one cation and one anion—that maintains the electrical neutrality of an ionic solid. NaN NaN NaN NaN Schottky defects A coupled pair of vacancies—one cation and one anion—that maintains the electrical neutrality of an ionic solid. NaN NaN NaN NaN scientific method The procedure that scientists use to search for answers to questions and solutions to problems. NaN NaN NaN NaN scientific method The procedure that scientists use to search for answers to questions and solutions to problems. NaN NaN NaN NaN scientific notation A system that expresses numbers in the form N × 10n, where N is greater than or equal to 1 and less than 10 (1 ≤ N < 10) and n is an integer that can be either positive or negative (100 = 1). The purpose of scientific notation is to simplify the manipulation of numbers with large or small magnitudes. NaN NaN NaN NaN scientific notation A system that expresses numbers in the form N × 10n, where N is greater than or equal to 1 and less than 10 (1 ≤ N < 10) and n is an integer that can be either positive or negative (100 = 1). The purpose of scientific notation is to simplify the manipulation of numbers with large or small magnitudes. NaN NaN NaN NaN second-order reaction A reaction whose rate is proportional to the square of the concentration of the reactant (for a reaction with the general form 2A → products) or is proportional to the product of the concentrations of two reactants (for a reaction with the general form A + B → products). NaN NaN NaN NaN second-order reaction A reaction whose rate is proportional to the square of the concentration of the reactant (for a reaction with the general form 2A → products) or is proportional to the product of the concentrations of two reactants (for a reaction with the general form A + B → products). NaN NaN NaN NaN seed crystal A solid sample of a substance that can be added to a supercooled liquid or a supersaturated solution to help induce crystallization. NaN NaN NaN NaN seed crystal A solid sample of a substance that can be added to a supercooled liquid or a supersaturated solution to help induce crystallization. NaN NaN NaN NaN seed crystal A solid sample of a substance that can be added to a supercooled liquid or a supersaturated solution to help induce crystallization. NaN NaN NaN NaN seed crystal A solid sample of a substance that can be added to a supercooled liquid or a supersaturated solution to help induce crystallization. NaN NaN NaN NaN semiconductors A substance such as Si and Ge that has a conductivity between that of metals and insulators. NaN NaN NaN NaN semiconductors A substance such as Si and Ge that has a conductivity between that of metals and insulators. NaN NaN NaN NaN semimetals Any element that lies adjacent to the zigzag line in the periodic table that runs from boron to astatine. Semimetals (also called metalloids) exhibit properties intermediate between those of metals and nonmetals. NaN NaN NaN NaN semimetals Any element that lies adjacent to the zigzag line in the periodic table that runs from boron to astatine. Semimetals (also called metalloids) exhibit properties intermediate between those of metals and nonmetals. NaN NaN NaN NaN sigma (σ) orbital A bonding molecular orbital in which the electron density along the internuclear axis and between the nuclei has cylindrical symmetry. NaN NaN NaN NaN sigma (σ) orbital A bonding molecular orbital in which the electron density along the internuclear axis and between the nuclei has cylindrical symmetry. NaN NaN NaN NaN sigma star (σ*) orbital An antibonding molecular orbital in which there is a region of zero electron probability (a nodal plane) perpendicular to the internuclear axis. NaN NaN NaN NaN sigma star (σ*) orbital An antibonding molecular orbital in which there is a region of zero electron probability (a nodal plane) perpendicular to the internuclear axis. NaN NaN NaN NaN significant figures Numbers that describe the value without exaggerating the degree to which it is known to be accurate. NaN NaN NaN NaN significant figures Numbers that describe the value without exaggerating the degree to which it is known to be accurate. NaN NaN NaN NaN single-displacement reactions A chemical reaction in which an ion in solution is displaced through oxidation of a metal. NaN NaN NaN NaN single-displacement reactions A chemical reaction in which an ion in solution is displaced through oxidation of a metal. NaN NaN NaN NaN sintering A process that fuses the grains of a ceramic into a dense, strong material. Sintering is used to produce high-strength ceramics. NaN NaN NaN NaN sintering A process that fuses the grains of a ceramic into a dense, strong material. Sintering is used to produce high-strength ceramics. NaN NaN NaN NaN sodium chloride structure The solid structure that results when the octahedral holes of an fcc lattice of anions are filled with cations. NaN NaN NaN NaN sodium chloride structure The solid structure that results when the octahedral holes of an fcc lattice of anions are filled with cations. NaN NaN NaN NaN sol-gel process A process used to manufacture ceramics by producing fine powders of ceramic oxides with uniformly sized particles. NaN NaN NaN NaN sol-gel process A process used to manufacture ceramics by producing fine powders of ceramic oxides with uniformly sized particles. NaN NaN NaN NaN solid electrolytes A solid material with a very high electrical conductivity. NaN NaN NaN NaN solid electrolytes A solid material with a very high electrical conductivity. NaN NaN NaN NaN solubility A measure of the how much of a solid substance remains dissolved in a given amount of a specified liquid at a specified temperature and pressure. NaN NaN NaN NaN solubility A measure of the how much of a solid substance remains dissolved in a given amount of a specified liquid at a specified temperature and pressure. NaN NaN NaN NaN solutions A homogeneous mixture of two or more substances in which the substances present in lesser amounts (the solutes) are dispersed uniformly throughout the substance present in greater amount (the solvent). NaN NaN NaN NaN sp hybrid orbital The two equivalent hybrid orbitals that result when one ns orbital and one np orbital are combined (hybridized). The two sp hybrid orbitals are oriented at 180° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp hybrid orbital The two equivalent hybrid orbitals that result when one ns orbital and one np orbital are combined (hybridized). The two sp hybrid orbitals are oriented at 180° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp2 hybrid atomic orbitals The three equivalent hybrid orbitals that result when one ns orbital and two np orbitals are combined (hybridized). The three sp2 hybrid orbitals are oriented in a plane at 120° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp2 hybrid atomic orbitals The three equivalent hybrid orbitals that result when one ns orbital and two np orbitals are combined (hybridized). The three sp2 hybrid orbitals are oriented in a plane at 120° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp3 hybrid atomic orbitals The four equivalent hybrid orbitals that result when one ns orbital and three np orbitals are combined (hybridized). The four sp3 hybrid orbitals point at the vertices of a tetrahedron, so they are oriented at 109.5° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp3 hybrid atomic orbitals The four equivalent hybrid orbitals that result when one ns orbital and three np orbitals are combined (hybridized). The four sp3 hybrid orbitals point at the vertices of a tetrahedron, so they are oriented at 109.5° from each other. They are equivalent in energy, and their energy is between the energy values associated with pure s and pure p orbitals. NaN NaN NaN NaN sp3d hybrid orbitals The five hybrid orbitals that result when one ns, three np, and one (n−1)d orbitals are combined (hybridized). NaN NaN NaN NaN sp3d hybrid orbitals The five hybrid orbitals that result when one ns, three np, and one (n−1)d orbitals are combined (hybridized). NaN NaN NaN NaN sp3d2 hybrid orbitals The six equivalent hybrid orbitals that result when one ns, three np, and two (n−1)d orbitals are combined (hybridized). NaN NaN NaN NaN sp3d2 hybrid orbitals The six equivalent hybrid orbitals that result when one ns, three np, and two (n−1)d orbitals are combined (hybridized). NaN NaN NaN NaN specific heat (Cs) The amount of energy needed to increase the temperature of 1 g of a substance by 1°C. The units of Cs are J/(g•°C). NaN NaN NaN NaN specific heat (Cs) The amount of energy needed to increase the temperature of 1 g of a substance by 1°C. The units of Cs are J/(g•°C). NaN NaN NaN NaN specific heat (Cs) The number of joules required to raise the temperature of 1 g of a substance by 1°C. NaN NaN NaN NaN specific heat (Cs) The number of joules required to raise the temperature of 1 g of a substance by 1°C. NaN NaN NaN NaN speed (v) The distance traveled by a wave per unit time. NaN NaN NaN NaN speed (v) The distance traveled by a wave per unit time. NaN NaN NaN NaN speed of light (c) The speed with which all forms of electromagnetic radiation travel in a vacuum. NaN NaN NaN NaN speed of light (c) The speed with which all forms of electromagnetic radiation travel in a vacuum. NaN NaN NaN NaN standard enthalpies of formation (ΔHfο) The enthalpy change for the formation of 1 mol of a compound from its component elements when the component elements are each in their standard states. The standard enthalpy of formation of any element in its most stable form is zero by definition. NaN NaN NaN NaN standard enthalpies of formation (ΔHfο) The enthalpy change for the formation of 1 mol of a compound from its component elements when the component elements are each in their standard states. The standard enthalpy of formation of any element in its most stable form is zero by definition. NaN NaN NaN NaN standard enthalpy of reaction (ΔHrxnο) The enthalpy change that occurs when a reaction is carried out with all reactants and products in their standard state. NaN NaN NaN NaN standard enthalpy of reaction (ΔHrxnο) The enthalpy change that occurs when a reaction is carried out with all reactants and products in their standard state. NaN NaN NaN NaN standard molar volume The volume of 1 mol of an ideal gas at STP (0°C and 1 atm pressure), which is 22.41 L. NaN NaN NaN NaN standard molar volume The volume of 1 mol of an ideal gas at STP (0°C and 1 atm pressure), which is 22.41 L. NaN NaN NaN NaN standard solution A solution whose concentration is precisely known. NaN NaN NaN NaN standard solution A solution whose concentration is precisely known. NaN NaN NaN NaN standard temperature and pressure (STP) The conditions 0°C (273.15 K) and 1 atm pressure for a gas. NaN NaN NaN NaN standard temperature and pressure (STP) The conditions 0°C (273.15 K) and 1 atm pressure for a gas. NaN NaN NaN NaN state function A property of a system whose magnitude depends on only the present state of the system, not its previous history. NaN NaN NaN NaN state function A property of a system whose magnitude depends on only the present state of the system, not its previous history. NaN NaN NaN NaN steric factor (p) The fraction of orientations of particles that result in a chemical reaction. NaN NaN NaN NaN steric factor (p) The fraction of orientations of particles that result in a chemical reaction. NaN NaN NaN NaN stock solution A commercially prepared solution of known concentration. NaN NaN NaN NaN stock solution A commercially prepared solution of known concentration. NaN NaN NaN NaN stoichiometric quantity The amount of product or reactant specified by the coefficients in a balanced chemical equation. NaN NaN NaN NaN stoichiometric quantity The amount of product or reactant specified by the coefficients in a balanced chemical equation. NaN NaN NaN NaN strong electrolytes An electrolyte that dissociates completely into ions when dissolved in water, thus producing an aqueous solution that conducts electricity very well. NaN NaN NaN NaN strong electrolytes An electrolyte that dissociates completely into ions when dissolved in water, thus producing an aqueous solution that conducts electricity very well. NaN NaN NaN NaN structural formulas A representation of a molecule that shows which atoms are bonded to one another and, in some cases, the approximate arrangement of atoms in space. NaN NaN NaN NaN structural formulas A representation of a molecule that shows which atoms are bonded to one another and, in some cases, the approximate arrangement of atoms in space. NaN NaN NaN NaN subshell A group of wave functions that have the same values of n and l. NaN NaN NaN NaN subshell A group of wave functions that have the same values of n and l. NaN NaN NaN NaN substitutional impurity A point defect that results when an impurity atom occupies a normal lattice site. NaN NaN NaN NaN substitutional impurity A point defect that results when an impurity atom occupies a normal lattice site. NaN NaN NaN NaN substrate The reactant in an enzyme-catalyzed reaction. NaN NaN NaN NaN substrate The reactant in an enzyme-catalyzed reaction. NaN NaN NaN NaN Superalloys A high-strength alloy based on cobalt, nickel, and iron, often of complex composition, that is used in applications that require mechanical strength, high surface stability, and resistance to high temperatures. NaN NaN NaN NaN Superalloys A high-strength alloy based on cobalt, nickel, and iron, often of complex composition, that is used in applications that require mechanical strength, high surface stability, and resistance to high temperatures. NaN NaN NaN NaN supercritical fluid The single, dense fluid phase that exists above the critical temperature of a substance. NaN NaN NaN NaN supercritical fluid The single, dense fluid phase that exists above the critical temperature of a substance. NaN NaN NaN NaN superheated liquid An unstable liquid at a temperature and pressure at which it should be a gas. NaN NaN NaN NaN superheated liquid An unstable liquid at a temperature and pressure at which it should be a gas. NaN NaN NaN NaN surface tension The energy required to increase the surface area of a liquid by a certain amount. Surface tension is measured in units of energy per area (e.g., J/m2). NaN NaN NaN NaN surface tension The energy required to increase the surface area of a liquid by a certain amount. Surface tension is measured in units of energy per area (e.g., J/m2). NaN NaN NaN NaN surfactants Substances (surface-active agents), such as soaps and detergents, that disrupt the attractive intermolecular interactions between molecules of a polar liquid, thereby reducing the surface tension of the liquid. NaN NaN NaN NaN surfactants Substances (surface-active agents), such as soaps and detergents, that disrupt the attractive intermolecular interactions between molecules of a polar liquid, thereby reducing the surface tension of the liquid. NaN NaN NaN NaN surroundings All the universe that is not the system; that is, system + surroundings = universe. NaN NaN NaN NaN surroundings All the universe that is not the system; that is, system + surroundings = universe. NaN NaN NaN NaN Système internationale d’unités (or SI) A system of units based on metric units that requires measurements to be expressed in decimal form. There are seven base units in the SI system. NaN NaN NaN NaN Système internationale d’unités (or SI) A system of units based on metric units that requires measurements to be expressed in decimal form. There are seven base units in the SI system. NaN NaN NaN NaN tetrahedral holes One of two kinds of holes in a face-centered cubic array of atoms or ions (the other is an octahedral hole). Tetrahedral holes are located between an atom at a corner and the three atoms at the centers of the adjacent faces of the face-centered cubic unit cell. An atom or ion in a tetrahedral hole has a coordination number of 4. NaN NaN NaN NaN tetrahedral holes One of two kinds of holes in a face-centered cubic array of atoms or ions (the other is an octahedral hole). Tetrahedral holes are located between an atom at a corner and the three atoms at the centers of the adjacent faces of the face-centered cubic unit cell. An atom or ion in a tetrahedral hole has a coordination number of 4. NaN NaN NaN NaN theoretical yield The maximum amount of product that can be formed from the reactants in a chemical reaction, which theoretically is the amount of product that would be obtained if the reaction occurred perfectly and the method of purifying the product were 100% efficient. NaN NaN NaN NaN theoretical yield The maximum amount of product that can be formed from the reactants in a chemical reaction, which theoretically is the amount of product that would be obtained if the reaction occurred perfectly and the method of purifying the product were 100% efficient. NaN NaN NaN NaN theory A statement that attempts to explain why nature behaves the way it does. NaN NaN NaN NaN theory A statement that attempts to explain why nature behaves the way it does. NaN NaN NaN NaN thermochemistry A branch of chemistry that describes the energy changes that occur during chemical reactions. NaN NaN NaN NaN thermochemistry A branch of chemistry that describes the energy changes that occur during chemical reactions. NaN NaN NaN NaN thermodynamic control The altering of reaction conditions so that a single desired product or set of products is present in significant quantities at equilibrium. NaN NaN NaN NaN thermodynamic control The altering of reaction conditions so that a single desired product or set of products is present in significant quantities at equilibrium. NaN NaN NaN NaN titration curve A plot of the pH of the solution being titrated versus the amount of acid or base (of known concentration) added. NaN NaN NaN NaN transition elements Any element in groups 3–12 in the periodic table. All of the transition elements are metals. NaN NaN NaN NaN transition elements Any element in groups 3–12 in the periodic table. All of the transition elements are metals. NaN NaN NaN NaN transition metals Any element in groups 3–12 in the periodic table. All of the transition elements are metals. NaN NaN NaN NaN transition metals Any element in groups 3–12 in the periodic table. All of the transition elements are metals. NaN NaN NaN NaN transition state Also called the activated complex, the arrangement of atoms that first forms when molecules are able to overcome the activation energy and react. NaN NaN NaN NaN transition state Also called the activated complex, the arrangement of atoms that first forms when molecules are able to overcome the activation energy and react. NaN NaN NaN NaN transmutation The process of converting one element to another. NaN NaN NaN NaN transmutation The process of converting one element to another. NaN NaN NaN NaN triads A set of three elements that have similar properties. NaN NaN NaN NaN triads A set of three elements that have similar properties. NaN NaN NaN NaN triple bond A chemical bond formed when two atoms share three pairs of electrons. NaN NaN NaN NaN triple bond A chemical bond formed when two atoms share three pairs of electrons. NaN NaN NaN NaN triple point The point in a phase diagram where the solid/liquid, liquid/gas, and solid/gas lines intersect; it represents the only combination of temperature and pressure at which all three phases are in equilibrium and can therefore exist simultaneously. NaN NaN NaN NaN triple point The point in a phase diagram where the solid/liquid, liquid/gas, and solid/gas lines intersect; it represents the only combination of temperature and pressure at which all three phases are in equilibrium and can therefore exist simultaneously. NaN NaN NaN NaN triprotic acid A compound that can donate three protons per molecule in separate steps. NaN NaN NaN NaN triprotic acid A compound that can donate three protons per molecule in separate steps. NaN NaN NaN NaN troposphere The lowest layer of the atmosphere, the troposphere extends from earth’s surface to an altitude of about 11–13 km (7–8 miles). The temperature of the troposphere decreases steadily with increasing altitude. NaN NaN NaN NaN troposphere The lowest layer of the atmosphere, the troposphere extends from earth’s surface to an altitude of about 11–13 km (7–8 miles). The temperature of the troposphere decreases steadily with increasing altitude. NaN NaN NaN NaN Tyndall effect The phenomenon of scattering a beam of visible light. NaN NaN NaN NaN Tyndall effect The phenomenon of scattering a beam of visible light. NaN NaN NaN NaN ultraviolet light High-energy radiation that cannot be detected by the human eye but can cause a wide variety of chemical reactions that are harmful to organisms. NaN NaN NaN NaN ultraviolet light High-energy radiation that cannot be detected by the human eye but can cause a wide variety of chemical reactions that are harmful to organisms. NaN NaN NaN NaN unit cell The smallest repeating unit of a crystal lattice. NaN NaN NaN NaN unit cell The smallest repeating unit of a crystal lattice. NaN NaN NaN NaN vacancy A point defect that consists of a single atom missing from a site in a crystal. NaN NaN NaN NaN vacancy A point defect that consists of a single atom missing from a site in a crystal. NaN NaN NaN NaN valence bond theory A localized bonding model that assumes that the strength of a covalent bond is proportional to the amount of overlap between atomic orbitals and that an atom can use different combinations of atomic orbitals (hybrids) to maximize the overlap between bonded atoms. NaN NaN NaN NaN valence bond theory A localized bonding model that assumes that the strength of a covalent bond is proportional to the amount of overlap between atomic orbitals and that an atom can use different combinations of atomic orbitals (hybrids) to maximize the overlap between bonded atoms. NaN NaN NaN NaN valence electrons Electrons in the outermost shell of an atom. NaN NaN NaN NaN valence electrons Electrons in the outermost shell of an atom. NaN NaN NaN NaN valence-shell electron-pair repulsion (VSEPR) model A model used to predict the shapes of many molecules and polyatomic ions, based on the idea that the lowest-energy arrangement for a compound is the one in which its electron pairs (bonding and nonbonding) are as far apart as possible. NaN NaN NaN NaN valence-shell electron-pair repulsion (VSEPR) model A model used to predict the shapes of many molecules and polyatomic ions, based on the idea that the lowest-energy arrangement for a compound is the one in which its electron pairs (bonding and nonbonding) are as far apart as possible. NaN NaN NaN NaN van der Waals atomic radius(rvdW) Half the internuclear distance between two nonbonded atoms in the solid. NaN NaN NaN NaN van der Waals atomic radius(rvdW) Half the internuclear distance between two nonbonded atoms in the solid. NaN NaN NaN NaN van der Waals equation A modification of the ideal gas law designed to describe the behavior of real gases by explicitly including the effects of molecular volume and intermolecular forces. NaN NaN NaN NaN van der Waals equation A modification of the ideal gas law designed to describe the behavior of real gases by explicitly including the effects of molecular volume and intermolecular forces. NaN NaN NaN NaN van der Waals forces The intermolecular forces known as dipole–dipole interactions and London dispersion forces. NaN NaN NaN NaN van der Waals forces The intermolecular forces known as dipole–dipole interactions and London dispersion forces. NaN NaN NaN NaN van’t Hoff factor(i) The ratio of the apparent number of particles in solution to the number predicted by the stoichiometry of the salt. NaN NaN NaN NaN van’t Hoff factor(i) The ratio of the apparent number of particles in solution to the number predicted by the stoichiometry of the salt. NaN NaN NaN NaN vapor pressure The pressure created over a liquid by the molecules of a liquid substance that have enough kinetic energy to escape to the vapor phase. NaN NaN NaN NaN vapor pressure The pressure created over a liquid by the molecules of a liquid substance that have enough kinetic energy to escape to the vapor phase. NaN NaN NaN NaN Viscosity (η) The resistance of a liquid to flow. NaN NaN NaN NaN Viscosity (η) The resistance of a liquid to flow. NaN NaN NaN NaN volume The amount of space occupied by a sample of matter. NaN NaN NaN NaN volume The amount of space occupied by a sample of matter. NaN NaN NaN NaN waters of hydration The loosely bound water molecules in hydrate compounds. These waters of hydration can often be removed by simply heating the compound. NaN NaN NaN NaN waters of hydration The loosely bound water molecules in hydrate compounds. These waters of hydration can often be removed by simply heating the compound. NaN NaN NaN NaN wave A periodic oscillation that transmits energy through space. NaN NaN NaN NaN wave A periodic oscillation that transmits energy through space. NaN NaN NaN NaN wave function (Ψ) A mathematical function that relates the location of an electron at a given point in space to the amplitude of its wave, which corresponds to its energy. NaN NaN NaN NaN wave function (Ψ) A mathematical function that relates the location of an electron at a given point in space to the amplitude of its wave, which corresponds to its energy. NaN NaN NaN NaN wave–particle duality A principle that matter and energy have properties typical of both waves and particles. NaN NaN NaN NaN wave–particle duality A principle that matter and energy have properties typical of both waves and particles. NaN NaN NaN NaN weak bases A base in which only a fraction of the molecules react with water to produce OH− and the corresponding cation. NaN NaN NaN NaN weak bases A base in which only a fraction of the molecules react with water to produce OH− and the corresponding cation. NaN NaN NaN NaN weak electrolytes A compound that produces relatively few ions when dissolved in water, thus producing an aqueous solution that conducts electricity poorly. NaN NaN NaN NaN weak electrolytes A compound that produces relatively few ions when dissolved in water, thus producing an aqueous solution that conducts electricity poorly. NaN NaN NaN NaN weight A force caused by the gravitational attraction that operates on an object. The weight of an object depends on its location (c.f. mass). NaN NaN NaN NaN weight A force caused by the gravitational attraction that operates on an object. The weight of an object depends on its location (c.f. mass). NaN NaN NaN NaN Work hardening The practice of introducing a dense network of dislocations throughout a solid, making it very tough and hard. NaN NaN NaN NaN Work hardening The practice of introducing a dense network of dislocations throughout a solid, making it very tough and hard. NaN NaN NaN NaN x-ray diffraction An technique used to obtain information about the structures of crystalline substances by using x-rays. NaN NaN NaN NaN x-ray diffraction An technique used to obtain information about the structures of crystalline substances by using x-rays. NaN NaN NaN NaN zeroth-order reaction A reaction whose rate is independent of concentration. NaN NaN NaN NaN zeroth-order reaction A reaction whose rate is independent of concentration. NaN NaN NaN NaN zinc blende structure The solid structure that results when half of the tetrahedral holes in an fcc lattice of anions are filled with cations with a 1:1 cation:anion ratio and a coordination number of 4. NaN NaN NaN NaN zinc blende structure The solid structure that results when half of the tetrahedral holes in an fcc lattice of anions are filled with cations with a 1:1 cation:anion ratio and a coordination number of 4. NaN NaN NaN NaN acid–base indicator A compound added in small amounts to an acid–base titration to signal the equivalence point by changing color. NaN NaN NaN NaN Acidic oxides An oxide that reacts with water to produce an acidic solution or dissolves in aqueous base. NaN NaN NaN NaN Acidic oxides An oxide that reacts with water to produce an acidic solution or dissolves in aqueous base. NaN NaN NaN NaN addition reaction A chemical reaction in which the components of a species A–B are added to adjacent atoms across a carbon-carbon multiple bond. NaN NaN NaN NaN addition reaction A chemical reaction in which the components of a species A–B are added to adjacent atoms across a carbon-carbon multiple bond. NaN NaN NaN NaN alkaline battery A battery that consists of a Leclanché cell adapted to operate under alkaline (basic) conditions. NaN NaN NaN NaN alkaline battery A battery that consists of a Leclanché cell adapted to operate under alkaline (basic) conditions. NaN NaN NaN NaN alpha (α) particle A helium nucleus: 4He. NaN NaN NaN NaN alpha (α) particle A helium nucleus: 4He. NaN NaN NaN NaN amperes (A) The fundamental SI unit of electric current; it is defined as the flow of 1 C/s past a given point: 1A = 1 C/s. NaN NaN NaN NaN amperes (A) The fundamental SI unit of electric current; it is defined as the flow of 1 C/s past a given point: 1A = 1 C/s. NaN NaN NaN NaN amphoteric oxides An oxide that can dissolve in acid to produce water and dissolve in base to produce a soluble complex. NaN NaN NaN NaN amphoteric oxides An oxide that can dissolve in acid to produce water and dissolve in base to produce a soluble complex. NaN NaN NaN NaN beta (β) decay A nuclear decay reaction in which a neutron is converted to a proton and a high-energy electron that is ejected from the nucleus as a β particle. NaN NaN NaN NaN beta (β) decay A nuclear decay reaction in which a neutron is converted to a proton and a high-energy electron that is ejected from the nucleus as a β particle. NaN NaN NaN NaN buffer capacity The amount of strong acid or strong base that a buffer solution can absorb before the pH changes dramatically. NaN NaN NaN NaN Buffers Solutions that maintain a relatively constant pH when an acid or a base is added. NaN NaN NaN NaN carbohydrates A polyhydroxy aldehyde or a polyhydroxy ketone with the general formula Cn(H2O)m. NaN NaN NaN NaN carbohydrates A polyhydroxy aldehyde or a polyhydroxy ketone with the general formula Cn(H2O)m. NaN NaN NaN NaN cathode One of two electrodes in an electrochemical cell, it is the site of the reduction half-reaction. NaN NaN NaN NaN cathode One of two electrodes in an electrochemical cell, it is the site of the reduction half-reaction. NaN NaN NaN NaN common ion effect The shift in equilibrium that results when a strong electrolyte containing one ion in common with a reaction system that is at equilibrium is added to the system. NaN NaN NaN NaN concentration cell An electrochemical cell in which the anode and the cathode compartments are identical except for the concentration of a reactant. NaN NaN NaN NaN concentration cell An electrochemical cell in which the anode and the cathode compartments are identical except for the concentration of a reactant. NaN NaN NaN NaN conformational isomer (or conformer) Isomers whose three-dimensional structures differ because of rotation about a σ bond. NaN NaN NaN NaN conformational isomer (or conformer) Isomers whose three-dimensional structures differ because of rotation about a σ bond. NaN NaN NaN NaN coordination compound A chemical compound with one or more metal complexes. NaN NaN NaN NaN coordination compound A chemical compound with one or more metal complexes. NaN NaN NaN NaN Corrosion A galvanic process by which metals deteriorate through oxidation—usually but not always to their oxides. NaN NaN NaN NaN Corrosion A galvanic process by which metals deteriorate through oxidation—usually but not always to their oxides. NaN NaN NaN NaN critical mass The minimum mass of a fissile isotope capable of supporting sustained fission. NaN NaN NaN NaN critical mass The minimum mass of a fissile isotope capable of supporting sustained fission. NaN NaN NaN NaN crown ethers A cyclic polyether that has four or more oxygen atoms separated by two or three carbon atoms. A central cavity can accommodate a metal ion coordinated to the ring of oxygen atoms. NaN NaN NaN NaN crown ethers A cyclic polyether that has four or more oxygen atoms separated by two or three carbon atoms. A central cavity can accommodate a metal ion coordinated to the ring of oxygen atoms. NaN NaN NaN NaN Cryptands Consisting of three (−OCH2CH2O−)n chains connected by two nitrogen atoms, this compound can completely encapsulate a metal ion of the appropriate size, coordinating to the metal by the lone pairs of electrons on each oxygen and the two nitrogen atoms. NaN NaN NaN NaN Cryptands Consisting of three (−OCH2CH2O−)n chains connected by two nitrogen atoms, this compound can completely encapsulate a metal ion of the appropriate size, coordinating to the metal by the lone pairs of electrons on each oxygen and the two nitrogen atoms. NaN NaN NaN NaN crystal field splitting energy The difference in energy between the eg set of d orbitals (dz2 and dx2−y2) and the t2g set of d orbitals (dxy, dxz, dyz) that results when the five d orbitals are placed in an octahedral crystal field. NaN NaN NaN NaN crystal field splitting energy The difference in energy between the eg set of d orbitals (dz2 and dx2−y2) and the t2g set of d orbitals (dxy, dxz, dyz) that results when the five d orbitals are placed in an octahedral crystal field. NaN NaN NaN NaN crystal field stabilization energy (CFSE) The additional stabilization of a metal complex by selective population of the lower-energy d orbitals (the t2g orbitals). NaN NaN NaN NaN crystal field stabilization energy (CFSE) The additional stabilization of a metal complex by selective population of the lower-energy d orbitals (the t2g orbitals). NaN NaN NaN NaN crystal field theory (CFT) A bonding model based on the assumption that metal–ligand interactions are purely electrostatic in nature, which explains many important properties of transition-metal complexes. NaN NaN NaN NaN crystal field theory (CFT) A bonding model based on the assumption that metal–ligand interactions are purely electrostatic in nature, which explains many important properties of transition-metal complexes. NaN NaN NaN NaN dehydration reaction A reaction that proceeds by eliminating the elements of water (H+ and OH−). NaN NaN NaN NaN dehydration reaction A reaction that proceeds by eliminating the elements of water (H+ and OH−). NaN NaN NaN NaN effective nuclear charge The nuclear charge an electron actually experiences because of shielding from other electrons closer to the nucleus. NaN NaN NaN NaN effective nuclear charge The nuclear charge an electron actually experiences because of shielding from other electrons closer to the nucleus. NaN NaN NaN NaN electrochemical cell An apparatus that generates electricity from a spontaneous oxidation–reduction (redox) reaction or, conversely, uses electricity to drive a nonspontaneous redox reaction. NaN NaN NaN NaN electrochemical cell An apparatus that generates electricity from a spontaneous oxidation–reduction (redox) reaction or, conversely, uses electricity to drive a nonspontaneous redox reaction. NaN NaN NaN NaN electrochemistry The study of the relationship between electricity and chemical reactions. NaN NaN NaN NaN electrochemistry The study of the relationship between electricity and chemical reactions. NaN NaN NaN NaN electrolysis An electrochemical process in which an external voltage is applied to an electrolytic cell to drive a nonspontaneous reaction. NaN NaN NaN NaN electrolysis An electrochemical process in which an external voltage is applied to an electrolytic cell to drive a nonspontaneous reaction. NaN NaN NaN NaN electron capture (EC) A nuclear decay reaction in which an electron in an inner shell reacts with a proton to produce a neutron. NaN NaN NaN NaN electron capture (EC) A nuclear decay reaction in which an electron in an inner shell reacts with a proton to produce a neutron. NaN NaN NaN NaN electrophile An electron-deficient species that needs electrons to complete its octet. NaN NaN NaN NaN electrophile An electron-deficient species that needs electrons to complete its octet. NaN NaN NaN NaN electrophilic aromatic substitution reactions A reaction in which a −H of an arene is replaced (substituted) by an electrophilic group in a two-step process. NaN NaN NaN NaN electrophilic aromatic substitution reactions A reaction in which a −H of an arene is replaced (substituted) by an electrophilic group in a two-step process. NaN NaN NaN NaN electroplating A process in which a layer of a second metal is deposited on the metal electrode that acts as the cathode during electrolysis. NaN NaN NaN NaN electroplating A process in which a layer of a second metal is deposited on the metal electrode that acts as the cathode during electrolysis. NaN NaN NaN NaN elimination reactions A chemical reaction in which adjacent atoms are removed, or “eliminated,” from a molecule, resulting in the formation of a multiple bond and a small molecule. NaN NaN NaN NaN elimination reactions A chemical reaction in which adjacent atoms are removed, or “eliminated,” from a molecule, resulting in the formation of a multiple bond and a small molecule. NaN NaN NaN NaN enthalpy (H) A state function that is the sum of the system’s internal energy E and the product of its pressure P and volume V: H=E+PV. NaN NaN NaN NaN enthalpy (H) A state function that is the sum of the system’s internal energy E and the product of its pressure P and volume V: H=E+PV. NaN NaN NaN NaN entropy (S) The degree of disorder in a thermodynamic system, which is directly proportional to the possible number of microstates. NaN NaN NaN NaN entropy (S) The degree of disorder in a thermodynamic system, which is directly proportional to the possible number of microstates. NaN NaN NaN NaN equivalence point The point in a titration where a stoichiometric amount of the titrant has been added. NaN NaN NaN NaN faraday (F) The charge on 1 mol of electrons; it is obtained by multiplying the charge on the electron by Avogadro’s number. NaN NaN NaN NaN faraday (F) The charge on 1 mol of electrons; it is obtained by multiplying the charge on the electron by Avogadro’s number. NaN NaN NaN NaN fermentation A process used by some chemotrophs to obtain energy from their environment; a chemical reaction in which both the oxidant and the reductant are organic compounds. NaN NaN NaN NaN fermentation A process used by some chemotrophs to obtain energy from their environment; a chemical reaction in which both the oxidant and the reductant are organic compounds. NaN NaN NaN NaN first law of thermodynamics The energy of the universe is constant: ΔEuniverse = ΔEsystem + ΔEsurroundings = 0. NaN NaN NaN NaN first law of thermodynamics The energy of the universe is constant: ΔEuniverse = ΔEsystem + ΔEsurroundings = 0. NaN NaN NaN NaN formation constant (Kf) The equilibrium constant for the formation of a complex ion from a hydrated metal ion; that is, for the reaction aA+bB⇌cC+dD, Kf=[C]c[D]d/[A]a[B]b. NaN NaN NaN NaN formation constant (Kf) The equilibrium constant for the formation of a complex ion from a hydrated metal ion; that is, for the reaction aA+bB⇌cC+dD, Kf=[C]c[D]d/[A]a[B]b. NaN NaN NaN NaN fuel cell A galvanic cell that requires a constant external supply of one or more reactants to generate electricity. NaN NaN NaN NaN fuel cell A galvanic cell that requires a constant external supply of one or more reactants to generate electricity. NaN NaN NaN NaN functional groups The structural units that chemists use to classify organic compounds and predict their reactivities under a given set of conditions. NaN NaN NaN NaN functional groups The structural units that chemists use to classify organic compounds and predict their reactivities under a given set of conditions. NaN NaN NaN NaN Gamma (γ) emission A nuclear decay reaction that results when a nucleus in an excited state releases energy in the form of a high-energy photon (a γ ray) when it returns to the ground state. NaN NaN NaN NaN Gamma (γ) emission A nuclear decay reaction that results when a nucleus in an excited state releases energy in the form of a high-energy photon (a γ ray) when it returns to the ground state. NaN NaN NaN NaN geometrical isomers Complexes that differ only in which ligands are adjacent to one another or directly across from one another in the coordination sphere of a metal. NaN NaN NaN NaN geometrical isomers Complexes that differ only in which ligands are adjacent to one another or directly across from one another in the coordination sphere of a metal. NaN NaN NaN NaN Gibbs free energy (G) A state function that is defined in terms of three other state functions—namely, enthalpy (H), entropy (S), and temperature (T): G=H−TS. NaN NaN NaN NaN Gibbs free energy (G) A state function that is defined in terms of three other state functions—namely, enthalpy (H), entropy (S), and temperature (T): G=H−TS. NaN NaN NaN NaN glass electrode An electrode used to measure the H+ ion concentration of a solution and consisting of an internal Ag/AgCl electrode immersed in a 1 M HCl solution that is separated from the solution by a very thin glass membrane. NaN NaN NaN NaN glass electrode An electrode used to measure the H+ ion concentration of a solution and consisting of an internal Ag/AgCl electrode immersed in a 1 M HCl solution that is separated from the solution by a very thin glass membrane. NaN NaN NaN NaN graphite intercalation compounds A compound that forms when heavier alkali metals react with carbon in the form of graphite and insert themselves between the sheets of carbon atoms. NaN NaN NaN NaN graphite intercalation compounds A compound that forms when heavier alkali metals react with carbon in the form of graphite and insert themselves between the sheets of carbon atoms. NaN NaN NaN NaN Grignard reagents An organometallic compound that has stabilized carbanions, whose general formula is RMgX, where X is Cl, Br, or I. NaN NaN NaN NaN Grignard reagents An organometallic compound that has stabilized carbanions, whose general formula is RMgX, where X is Cl, Br, or I. NaN NaN NaN NaN group transfer reactions Reactions involving the transfer of a group, catalyzed by metal ions that do not change their oxidation states during the reaction. NaN NaN NaN NaN group transfer reactions Reactions involving the transfer of a group, catalyzed by metal ions that do not change their oxidation states during the reaction. NaN NaN NaN NaN half-reactions Reactions that represent either the oxidation half or the reduction half of an oxidation–reduction (redox) reaction. NaN NaN NaN NaN half-reactions Reactions that represent either the oxidation half or the reduction half of an oxidation–reduction (redox) reaction. NaN NaN NaN NaN Henderson-Hasselbalch equation A rearranged version of the equilibrium constant expression that provides a direct way to calculate the pH of a buffer solution: pH = pKa + log([base]/[acid]). NaN NaN NaN NaN hydrolysis reactions A chemical reaction in which a salt reacts with water to yield an acidic or a basic solution. NaN NaN NaN NaN inert-pair effect The empirical observation that the heavier elements of groups 13–17 often have oxidation states that are lower by 2 than the maximum predicted for their group. NaN NaN NaN NaN inert-pair effect The empirical observation that the heavier elements of groups 13–17 often have oxidation states that are lower by 2 than the maximum predicted for their group. NaN NaN NaN NaN internal energy (E) A state function that is the sum of the kinetic and potential energies of all a system’s components. NaN NaN NaN NaN internal energy (E) A state function that is the sum of the kinetic and potential energies of all a system’s components. NaN NaN NaN NaN ion pair A cation and an anion that are in intimate contact in solution rather than separated by solvent. An ion pair can be viewed as a species that is intermediate between the ionic solid and the completely dissociated ions in solution. NaN NaN NaN NaN ion pair A cation and an anion that are in intimate contact in solution rather than separated by solvent. An ion pair can be viewed as a species that is intermediate between the ionic solid and the completely dissociated ions in solution. NaN NaN NaN NaN ion product (Q) A quantity that has precisely the same form as the solubility product for the dissolution of a sparingly soluble salt, except that the concentrations used are not necessarily equilibrium concentrations. NaN NaN NaN NaN ion product (Q) A quantity that has precisely the same form as the solubility product for the dissolution of a sparingly soluble salt, except that the concentrations used are not necessarily equilibrium concentrations. NaN NaN NaN NaN ion pumps A complex assembly of proteins that selectively transport ions across cell membranes by their high affinity for ions of a certain charge and radius. NaN NaN NaN NaN ion pumps A complex assembly of proteins that selectively transport ions across cell membranes by their high affinity for ions of a certain charge and radius. NaN NaN NaN NaN Ion-selective electrodes An electrode whose potential depends on only the concentration of a particular species in solution. NaN NaN NaN NaN Ion-selective electrodes An electrode whose potential depends on only the concentration of a particular species in solution. NaN NaN NaN NaN ionizing radiation Radiation of a high enough energy to transfer some as it passes through matter to one or more atoms with which it collides. If enough energy is transferred, electrons can be excited to very high energy levels, resulting in the formation of positively charged ions. NaN NaN NaN NaN ionizing radiation Radiation of a high enough energy to transfer some as it passes through matter to one or more atoms with which it collides. If enough energy is transferred, electrons can be excited to very high energy levels, resulting in the formation of positively charged ions. NaN NaN NaN NaN ionophores A molecule that facilitates the transport of metal ions across membranes. NaN NaN NaN NaN ionophores A molecule that facilitates the transport of metal ions across membranes. NaN NaN NaN NaN irreversible process A process in which the intermediate states between the extremes are not equilibrium states, so change occurs spontaneously in only one direction. NaN NaN NaN NaN irreversible process A process in which the intermediate states between the extremes are not equilibrium states, so change occurs spontaneously in only one direction. NaN NaN NaN NaN isomers Two or more compounds with the same molecular formula but different arrangements of their atoms. NaN NaN NaN NaN isomers Two or more compounds with the same molecular formula but different arrangements of their atoms. NaN NaN NaN NaN Jahn–Teller theorem A theory that states that a non-linear molecule with a spatially degenerate electronic ground state will undergo a geometrical distortion to remove the degeneracy and lower the overall energy of the system. NaN NaN NaN NaN Jahn–Teller theorem A theory that states that a non-linear molecule with a spatially degenerate electronic ground state will undergo a geometrical distortion to remove the degeneracy and lower the overall energy of the system. NaN NaN NaN NaN lead–acid battery A battery consisting of a plate or grid of spongy lead metal, a cathode containing powdered PbO2, and an electrolyte that is usually an aqueous solution of H2SO4. NaN NaN NaN NaN lead–acid battery A battery consisting of a plate or grid of spongy lead metal, a cathode containing powdered PbO2, and an electrolyte that is usually an aqueous solution of H2SO4. NaN NaN NaN NaN Leclanché dry cell A battery consisting of an electrolyte that is an acidic water-based paste containing MnO2, NH4Cl, ZnCl2, graphite, and starch. NaN NaN NaN NaN Leclanché dry cell A battery consisting of an electrolyte that is an acidic water-based paste containing MnO2, NH4Cl, ZnCl2, graphite, and starch. NaN NaN NaN NaN leveling effect The phenomenon that makes H3O+ the strongest acid that can exist in water. Any species that is a stronger acid than H3O+ is leveled to the strength of H3O+ in aqueous solution. NaN NaN NaN NaN ligands An ion or a molecule that contains one or more pairs of electrons that can be shared with the central metal in a metal complex. NaN NaN NaN NaN ligands An ion or a molecule that contains one or more pairs of electrons that can be shared with the central metal in a metal complex. NaN NaN NaN NaN Lipids A family of compounds that includes fats, waxes, some vitamins, and steroids and characterized by their insolubility in water. NaN NaN NaN NaN Lipids A family of compounds that includes fats, waxes, some vitamins, and steroids and characterized by their insolubility in water. NaN NaN NaN NaN lithium–iodine battery A battery that consists of an anode of lithium metal and a cathode containing a solid complex of I2, with a layer of solid LiI in between that allows the diffusion of Li+ ions. NaN NaN NaN NaN lithium–iodine battery A battery that consists of an anode of lithium metal and a cathode containing a solid complex of I2, with a layer of solid LiI in between that allows the diffusion of Li+ ions. NaN NaN NaN NaN mass defect The difference between the sum of the masses of the components of an atom (protons, neutrons, and electrons) and the measured atomic mass. NaN NaN NaN NaN mass defect The difference between the sum of the masses of the components of an atom (protons, neutrons, and electrons) and the measured atomic mass. NaN NaN NaN NaN mer An isomer in which three ligands lie on a spherical meridian. NaN NaN NaN NaN mer An isomer in which three ligands lie on a spherical meridian. NaN NaN NaN NaN metalloenzyme A protein that contains one or more tightly bound metal ions and catalyzes a biochemical reaction. NaN NaN NaN NaN metalloenzyme A protein that contains one or more tightly bound metal ions and catalyzes a biochemical reaction. NaN NaN NaN NaN Metallurgy A set of processes by which metals are extracted from their ores and converted to more useful forms. NaN NaN NaN NaN Metallurgy A set of processes by which metals are extracted from their ores and converted to more useful forms. NaN NaN NaN NaN midpoint The point in an acid–base titration at which exactly enough acid (or base) has been added to neutralize one-half of the base (or the acid) originally present: [HA]=[A−]. NaN NaN NaN NaN Nernst equation An equation for calculating cell potentials (Ecell) under nonstandard conditions; it can be used to determine the direction of spontaneous reaction for any redox reaction under an conditions: Ecell=Ecell°−(RT/nF)ln Q. NaN NaN NaN NaN Nernst equation An equation for calculating cell potentials (Ecell) under nonstandard conditions; it can be used to determine the direction of spontaneous reaction for any redox reaction under an conditions: Ecell=Ecell°−(RT/nF)ln Q. NaN NaN NaN NaN nickel–cadmium A type of battery that consists of a water-based cell with a cadmium anode and a highly oxidized nickel cathode. NaN NaN NaN NaN nickel–cadmium A type of battery that consists of a water-based cell with a cadmium anode and a highly oxidized nickel cathode. NaN NaN NaN NaN Nonionizing radiation Radiation that is relatively low in energy. When it collides with an atom in a molecule or ion, most or all of its energy can be absorbed without causing a structural or a chemical change. NaN NaN NaN NaN Nonionizing radiation Radiation that is relatively low in energy. When it collides with an atom in a molecule or ion, most or all of its energy can be absorbed without causing a structural or a chemical change. NaN NaN NaN NaN nuclear binding energy The amount of energy released when a nucleus forms from its component nucleons, which corresponds to the mass defect of the nucleus. NaN NaN NaN NaN nuclear binding energy The amount of energy released when a nucleus forms from its component nucleons, which corresponds to the mass defect of the nucleus. NaN NaN NaN NaN nuclear fission The splitting of a heavy nucleus into two lighter ones. NaN NaN NaN NaN nuclear fission The splitting of a heavy nucleus into two lighter ones. NaN NaN NaN NaN Nuclear fusion The combining of two light nuclei to produce a heavier, more stable nucleus. NaN NaN NaN NaN Nuclear fusion The combining of two light nuclei to produce a heavier, more stable nucleus. NaN NaN NaN NaN nuclear transmutation reaction A nuclear reaction in which a nucleus reacts with a subatomic particle or another nuleus to give a product nucleus that is more massive than the starting material. NaN NaN NaN NaN nuclear transmutation reaction A nuclear reaction in which a nucleus reacts with a subatomic particle or another nuleus to give a product nucleus that is more massive than the starting material. NaN NaN NaN NaN Nucleic acids A linear polymer of nucleotides that is the basic structural component of DNA and RNA. NaN NaN NaN NaN Nucleic acids A linear polymer of nucleotides that is the basic structural component of DNA and RNA. NaN NaN NaN NaN nucleophile An electron-rich species that has a pair of electrons available to be shared with another atom. NaN NaN NaN NaN nucleophile An electron-rich species that has a pair of electrons available to be shared with another atom. NaN NaN NaN NaN nuclide An atom with a particular number of nucleons. NaN NaN NaN NaN nuclide An atom with a particular number of nucleons. NaN NaN NaN NaN organometallic compounds A compound that contains a metal covalently bonded to a carbon atom of an organic species. NaN NaN NaN NaN organometallic compounds A compound that contains a metal covalently bonded to a carbon atom of an organic species. NaN NaN NaN NaN overvoltage The voltage that must be applied in electrolysis in addition to the calculated (theoretical) value to overcome factors such as a high activation energy and the formation of bubbles on a surface. NaN NaN NaN NaN overvoltage The voltage that must be applied in electrolysis in addition to the calculated (theoretical) value to overcome factors such as a high activation energy and the formation of bubbles on a surface. NaN NaN NaN NaN oxidant A substance that is capable of accepting electrons and in the process is reduced. NaN NaN NaN NaN oxidant A substance that is capable of accepting electrons and in the process is reduced. NaN NaN NaN NaN photosynthesis The fundamental reaction by which all green plants and algae obtain energy from sunlight in which CO2 is photochemically reduced to a carbon compound such as glucose. Oxygen in water is concurrently oxidized to O2. NaN NaN NaN NaN photosynthesis The fundamental reaction by which all green plants and algae obtain energy from sunlight in which CO2 is photochemically reduced to a carbon compound such as glucose. Oxygen in water is concurrently oxidized to O2. NaN NaN NaN NaN positron emission A nuclear decay reaction in which a proton is transformed into a neutron, and a high-energy positron is emitted. NaN NaN NaN NaN positron emission A nuclear decay reaction in which a proton is transformed into a neutron, and a high-energy positron is emitted. NaN NaN NaN NaN potential (Ecell) Related to the energy needed to move a charged particle in an electric field, it is the difference in electrical potential beween two half-reactions. NaN NaN NaN NaN potential (Ecell) Related to the energy needed to move a charged particle in an electric field, it is the difference in electrical potential beween two half-reactions. NaN NaN NaN NaN proteins A biological polymer with more than 50 amino acid residues linked together by amide bonds. NaN NaN NaN NaN proteins A biological polymer with more than 50 amino acid residues linked together by amide bonds. NaN NaN NaN NaN pyrolysis reaction A high-temperature decomposition reaction that can be used to form fibers of synthetic polymers. NaN NaN NaN NaN pyrolysis reaction A high-temperature decomposition reaction that can be used to form fibers of synthetic polymers. NaN NaN NaN NaN qualitative analysis A procedure for determining the identity of metal ions present in a mixture that does not include information about their amounts. NaN NaN NaN NaN qualitative analysis A procedure for determining the identity of metal ions present in a mixture that does not include information about their amounts. NaN NaN NaN NaN quaternary ammonium salts A salt that consist of an anion and a cation in which all four H atoms of the ammonium ion (NH4+) are replaced by alkyl groups. NaN NaN NaN NaN quaternary ammonium salts A salt that consist of an anion and a cation in which all four H atoms of the ammonium ion (NH4+) are replaced by alkyl groups. NaN NaN NaN NaN rad (radiation absorbed dose) A unit used to measure the effects of radiation on biological tissues; the amount of radiation that causes 0.01 J of energy to be absorbed by 1 kg of matter. NaN NaN NaN NaN rad (radiation absorbed dose) A unit used to measure the effects of radiation on biological tissues; the amount of radiation that causes 0.01 J of energy to be absorbed by 1 kg of matter. NaN NaN NaN NaN radical Highly reactive species that have an unpaired valence electron. NaN NaN NaN NaN radical Highly reactive species that have an unpaired valence electron. NaN NaN NaN NaN radioactive decay series A series of sequential alpha- and beta-decay reactions that occur until a stable nucleus is finally obtained. NaN NaN NaN NaN radioactive decay series A series of sequential alpha- and beta-decay reactions that occur until a stable nucleus is finally obtained. NaN NaN NaN NaN radioisotopes An isotope that emits radiation. NaN NaN NaN NaN radioisotopes An isotope that emits radiation. NaN NaN NaN NaN reference electrode An electrode in an galvanic cell whose potential is unaffected by the properties of the solution. NaN NaN NaN NaN reference electrode An electrode in an galvanic cell whose potential is unaffected by the properties of the solution. NaN NaN NaN NaN rem (roentgen equivalent in man) A unit that describes the actual amount of tissue damage caused by a given amount of radiation and equal to the number of rads multiplied by the RBE. NaN NaN NaN NaN rem (roentgen equivalent in man) A unit that describes the actual amount of tissue damage caused by a given amount of radiation and equal to the number of rads multiplied by the RBE. NaN NaN NaN NaN respiration A process by which chemotrophs obtain energy from their environment; the overall reaction of respiration is the reverse of photosynthesis. Respiration is the combustion of a carbon compound such as glucose to CO2 and water. NaN NaN NaN NaN respiration A process by which chemotrophs obtain energy from their environment; the overall reaction of respiration is the reverse of photosynthesis. Respiration is the combustion of a carbon compound such as glucose to CO2 and water. NaN NaN NaN NaN sacrificial electrodes An electrode containing a more reactive metal that is attached to a metal object to inhibit that object’s corrosion. NaN NaN NaN NaN sacrificial electrodes An electrode containing a more reactive metal that is attached to a metal object to inhibit that object’s corrosion. NaN NaN NaN NaN salt bridge A U-shaped tube inserted into both solutions of a galvanic cell that contains a concentrated liquid or gelled electrolyte and completes the circuit between the anode and the cathode. NaN NaN NaN NaN salt bridge A U-shaped tube inserted into both solutions of a galvanic cell that contains a concentrated liquid or gelled electrolyte and completes the circuit between the anode and the cathode. NaN NaN NaN NaN saturated calomel electrode (SCE) A reference electrode that consists of a platinum wire inserted into a moist paste of liquid mercury (calomel; Hg2Cl2) and KCl in an interior cell, which is surrounded by an aqueous KCl solution. NaN NaN NaN NaN saturated calomel electrode (SCE) A reference electrode that consists of a platinum wire inserted into a moist paste of liquid mercury (calomel; Hg2Cl2) and KCl in an interior cell, which is surrounded by an aqueous KCl solution. NaN NaN NaN NaN second law of thermodynamics The entropy of the universe remains constant in a reversible process, whereas the entropy of the universe increases in an irreversible (spontaneous) process. NaN NaN NaN NaN second law of thermodynamics The entropy of the universe remains constant in a reversible process, whereas the entropy of the universe increases in an irreversible (spontaneous) process. NaN NaN NaN NaN siderophores An organic ligand that has a high affinity for Fe(III) and is secreted into the surrounding medium to increase the total concentration of dissolved iron. NaN NaN NaN NaN siderophores An organic ligand that has a high affinity for Fe(III) and is secreted into the surrounding medium to increase the total concentration of dissolved iron. NaN NaN NaN NaN silver–silver chloride electrode A reference electrode that consists of a silver wire coated with a very thin layer of AgCl and dipped into a chloride ion solution with a fixed concentration. NaN NaN NaN NaN silver–silver chloride electrode A reference electrode that consists of a silver wire coated with a very thin layer of AgCl and dipped into a chloride ion solution with a fixed concentration. NaN NaN NaN NaN soft acids An acid with the highest affinity for soft bases. It tends to be a cation of a less electropositive metal. NaN NaN NaN NaN soft acids An acid with the highest affinity for soft bases. It tends to be a cation of a less electropositive metal. NaN NaN NaN NaN solubility product (Ksp) The equilibrium constant expression for the dissolution of a sparingly soluble salt that includes the concentration of a pure solid, which is a constant. NaN NaN NaN NaN solubility product (Ksp) The equilibrium constant expression for the dissolution of a sparingly soluble salt that includes the concentration of a pure solid, which is a constant. NaN NaN NaN NaN specific rotation The amount (in degrees) by which the plane of polarized light is rotated when the light is passed through a solution that contains 1.0 g of a solute per 1.0 mL of solvent in a tube 10.0 cm long. NaN NaN NaN NaN specific rotation The amount (in degrees) by which the plane of polarized light is rotated when the light is passed through a solution that contains 1.0 g of a solute per 1.0 mL of solvent in a tube 10.0 cm long. NaN NaN NaN NaN spectrochemical series An ordering of ligands by their crystal field splitting energies. NaN NaN NaN NaN spectrochemical series An ordering of ligands by their crystal field splitting energies. NaN NaN NaN NaN spin-pairing energy (P) The energy that must be overcome to place an electron in an orbital that already has one electron. NaN NaN NaN NaN spin-pairing energy (P) The energy that must be overcome to place an electron in an orbital that already has one electron. NaN NaN NaN NaN spontaneous fission A nuclear decay reaction in which the nucleus breaks into two pieces with different atomic numbers and atomic masses. NaN NaN NaN NaN spontaneous fission A nuclear decay reaction in which the nucleus breaks into two pieces with different atomic numbers and atomic masses. NaN NaN NaN NaN standard cell potential The potential of an electrochemical cell measured under standard conditions (1 M for solutions, 1 atm for gases, and pure solids or pure liquids for other substances) and at a fixed temperature (usually 298 K). NaN NaN NaN NaN standard cell potential The potential of an electrochemical cell measured under standard conditions (1 M for solutions, 1 atm for gases, and pure solids or pure liquids for other substances) and at a fixed temperature (usually 298 K). NaN NaN NaN NaN standard electrode potential The potential of a half-reaction measured against the SHE under standard conditions. NaN NaN NaN NaN standard electrode potential The potential of a half-reaction measured against the SHE under standard conditions. NaN NaN NaN NaN standard free energy of formation (ΔGf°) The change in free energy that occurs when 1 mol of a substance in its standard state is formed from the component elements in their standard states: ΔG°f=ΔH°f−TΔS°f. NaN NaN NaN NaN standard free energy of formation (ΔGf°) The change in free energy that occurs when 1 mol of a substance in its standard state is formed from the component elements in their standard states: ΔG°f=ΔH°f−TΔS°f. NaN NaN NaN NaN standard free-energy change (ΔG°) The change in free energy when one substance or a set of substances in their standard states is converted to one or more other sustances, also in their standard states: ΔG°=ΔH°−TΔS°. NaN NaN NaN NaN standard free-energy change (ΔG°) The change in free energy when one substance or a set of substances in their standard states is converted to one or more other sustances, also in their standard states: ΔG°=ΔH°−TΔS°. NaN NaN NaN NaN standard hydrogen electrode (SHE) The electrode chosen as the reference for all other electrodes, which has been assigned a standard potential of 0 V and consists of a Pt wire in contact with an aqueous solution that contains 1 M H + in equilibrium with H2 gas at a pressure of 1 atm at the Pt-solution interface. NaN NaN NaN NaN standard hydrogen electrode (SHE) The electrode chosen as the reference for all other electrodes, which has been assigned a standard potential of 0 V and consists of a Pt wire in contact with an aqueous solution that contains 1 M H + in equilibrium with H2 gas at a pressure of 1 atm at the Pt-solution interface. NaN NaN NaN NaN standard molar entropy (S°) The entropy of 1 mol of a substance at a standard temperature of 298 K. NaN NaN NaN NaN standard molar entropy (S°) The entropy of 1 mol of a substance at a standard temperature of 298 K. NaN NaN NaN NaN state function A property of a system whose magnitude depends on only the present state of the system, not its previous history. NaN NaN NaN NaN state function A property of a system whose magnitude depends on only the present state of the system, not its previous history. NaN NaN NaN NaN stereoisomers Molecules that have the same connectivity but whose component atoms have different orientations in space. NaN NaN NaN NaN stereoisomers Molecules that have the same connectivity but whose component atoms have different orientations in space. NaN NaN NaN NaN strong nuclear force An extremely powerful but very short-range attractive force between nucleons that keeps the nucleus of an atom from flying apart (due to electrostatic repulsions between protons). NaN NaN NaN NaN strong nuclear force An extremely powerful but very short-range attractive force between nucleons that keeps the nucleus of an atom from flying apart (due to electrostatic repulsions between protons). NaN NaN NaN NaN structural isomers Two or more compounds that have the same molecular formula but differ in which atoms are bonded to one another. NaN NaN NaN NaN structural isomers Two or more compounds that have the same molecular formula but differ in which atoms are bonded to one another. NaN NaN NaN NaN structural isomers Isomers that have the same molecular formula but differ in which atoms are bonded to one another. NaN NaN NaN NaN structural isomers Isomers that have the same molecular formula but differ in which atoms are bonded to one another. NaN NaN NaN NaN substitution reaction A chemical reaction in which one atom or a group of atoms in a substance is replaced by another atom or a group of atoms from another substance. NaN NaN NaN NaN substitution reaction A chemical reaction in which one atom or a group of atoms in a substance is replaced by another atom or a group of atoms from another substance. NaN NaN NaN NaN superheavy elements An element with an atomic number near the magic number of 126. NaN NaN NaN NaN superheavy elements An element with an atomic number near the magic number of 126. NaN NaN NaN NaN thermodynamics The study of the interrelationships among heat, work, and the energy content of a system at equilibrium. NaN NaN NaN NaN thermonuclear reactions A nuclear reaction that requires a great deal of thermal energy to initiate the reaction. NaN NaN NaN NaN thermonuclear reactions A nuclear reaction that requires a great deal of thermal energy to initiate the reaction. NaN NaN NaN NaN third law of thermodynamics The entropy of any perfectly ordered, crystalline substance at absolute zero is zero. NaN NaN NaN NaN third law of thermodynamics The entropy of any perfectly ordered, crystalline substance at absolute zero is zero. NaN NaN NaN NaN three-center bond (or electron-deficient bond) A bond in which a hydride ion bridges two electropositive atoms. NaN NaN NaN NaN three-center bond (or electron-deficient bond) A bond in which a hydride ion bridges two electropositive atoms. NaN NaN NaN NaN titration curve A plot of the pH of the solution being titrated versus the amount of acid or base (of known concentration) added. NaN NaN NaN NaN transuranium elements An artificial element that has been prepared by bombarding suitable target nuclei with smaller particles. NaN NaN NaN NaN transuranium elements An artificial element that has been prepared by bombarding suitable target nuclei with smaller particles. NaN NaN NaN NaN tritium A rare isotope of hydrogen that consists of one proton, two neutrons, and one electron. NaN NaN NaN NaN tritium A rare isotope of hydrogen that consists of one proton, two neutrons, and one electron. NaN NaN NaN NaN