8.1: States of Matter and Their Changes Another way that we can describe the properties of matter is the state (also called phase). The amount of energy in molecules of matter determines the state of matter. Matter can exist in one of several different states, including a gas, liquid, or solid state. 8.2: Intermolecular Forces A phase is a form of matter that has the same physical properties throughout. Molecules interact with each other through various forces: ionic and covalent bonds, dipole-dipole interactions, hydrogen bonding, and dispersion forces. 8.3: Gases and the Kinetic-Molecular Theory By integrating the knowledge of gaseous behavior from the gas laws and kinetic theory, we gain deeper insights into gases behavior. 8.4: Pressure Gases exert pressure, which is force per unit area. The pressure of a gas may be expressed in the SI unit of pascal or kilopascal, as well as in many other units including torr, atmosphere, and bar. Atmospheric pressure is measured using a barometer; other gas pressures can be measured using one of several types of manometers. 8.5: Boyle’s Law - The Relation between Volume and Pressure The behavior of gases can be modeled with gas laws. Boyle's law relates a gas's pressure and volume at constant temperature and amount. 8.6: Charles’s Law- The Relation between Volume and Temperature What happens to the volume of a gas as its heated? From experience, you probably know the answer. This article will explore the connection between volume and temperature. 8.7: Gay-Lussac's Law- The Relationship Between Pressure and Temperature According to Gay-Lussac’s law, for a given amount of gas held at constant volume, the pressure is proportional to the absolute temperature. 8.8: The Combined Gas Law The combined gas law relates pressure, volume, and temperature of a fixed amount of gas. 8.9: Avogadro’s Law - The Relation between Volume and Molar Amount Avogadro showed that the volume of a gas is directly proportional to the number of moles of gas (Avogadro’s law). 8.10: The Ideal Gas Law The ideal gas law relates the four independent physical properties of a gas at any time. The ideal gas law can be used in stoichiometry problems with chemical reactions that involve gases. 8.11: Partial Pressure and Dalton's Law The pressure of a gas in a gas mixture is termed the partial pressure. Dalton's law of partial pressure says that the total pressure in a gas mixture is the sum of the individual partial pressures. 8.12: Liquids The intermolecular interactions between molecules in a liquid can be used to describe properties such as boiling point, vapor pressure, and surface tension. 8.13: Solids Solids can be divided into amorphous solids and crystalline solids. Crystalline solids can be ionic, molecular, covalent network, or metallic. 8.14: Changes of State Calculations There is an energy change associated with any phase change. There is an energy change associated with any phase change.