start acid anhydride compound that reacts with water to form an acid or acidic solution alkaline earth metal any of the metals (beryllium, magnesium, calcium, strontium, barium, and radium) occupying group 2 of the periodic table; they are reactive, divalent metals that form basic oxides allotropes two or more forms of the same element, in the same physical state, with different chemical structures amorphous solid material such as a glass that does not have a regular repeating component to its three-dimensional structure; a solid but not a crystal base anhydride metal oxide that behaves as a base towards acids bicarbonate anion salt of the hydrogen carbonate ion, bismuth heaviest member of group 15; a less reactive metal than other representative metals borate compound containing boron-oxygen bonds, typically with clusters or chains as a part of the chemical structure carbonate salt of the anion often formed by the reaction of carbon dioxide with bases chemical reduction method of preparing a representative metal using a reducing agent chlor-alkali process electrolysis process for the synthesis of chlorine and sodium hydroxide disproportionation reaction chemical reaction where a single reactant is simultaneously reduced and oxidized; it is both the reducing agent and the oxidizing agent Downs cell electrochemical cell used for the commercial preparation of metallic sodium (and chlorine) from molten sodium chloride Frasch process important in the mining of free sulfur from enormous underground deposits Haber process main industrial process used to produce ammonia from nitrogen and hydrogen; involves the use of an iron catalyst and elevated temperatures and pressures halide compound containing an anion of a group 17 element in the 1− oxidation state (fluoride, F − ; chloride, Cl − ; bromide, Br − ; and iodide, I − ) Hall–Héroult cell electrolysis apparatus used to isolate pure aluminum metal from a solution of alumina in molten cryolite hydrogen carbonate salt of carbonic acid, H 2 CO 3 (containing the anion in which one hydrogen atom has been replaced; an acid carbonate; also known as bicarbonate ion hydrogen halide binary compound formed between hydrogen and the halogens: HF, HCl, HBr, and HI hydrogen sulfate ion hydrogen sulfite ion hydrogenation addition of hydrogen (H 2 ) to reduce a compound hydroxide compound of a metal with the hydroxide ion OH − or the group −OH interhalogen compound formed from two or more different halogens metal (representative) atoms of the metallic elements of groups 1, 2, 12, 13, 14, 15, and 16, which form ionic compounds by losing electrons from their outer s or p orbitals metalloid element that has properties that are between those of metals and nonmetals; these elements are typically semiconductors nitrate ion; salt of nitric acid nitrogen fixation formation of nitrogen compounds from molecular nitrogen Ostwald process industrial process used to convert ammonia into nitric acid oxide binary compound of oxygen with another element or group, typically containing O 2− ions or the group –O– or =O ozone allotrope of oxygen; O 3 passivation metals with a protective nonreactive film of oxide or other compound that creates a barrier for chemical reactions; physical or chemical removal of the passivating film allows the metals to demonstrate their expected chemical reactivity peroxide molecule containing two oxygen atoms bonded together or as the anion, photosynthesis process whereby light energy promotes the reaction of water and carbon dioxide to form carbohydrates and oxygen; this allows photosynthetic organisms to store energy Pidgeon process chemical reduction process used to produce magnesium through the thermal reaction of magnesium oxide with silicon polymorph variation in crystalline structure that results in different physical properties for the resulting compound representative element element where the s and p orbitals are filling representative metal metal among the representative elements silicate compound containing silicon-oxygen bonds, with silicate tetrahedra connected in rings, sheets, or three-dimensional networks, depending on the other elements involved in the formation of the compounds sulfate ion sulfite ion superoxide oxide containing the anion end