The Chemistry of Carbon Compounds

Gold:  source: Internet Gold is a chemical element. The symbol of gold is Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In a pure form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and soil under standard conditions. Gold often occurs in free elemental form, as grains, in rocks, in veins. It occurs in a solid solution series with the native element silver, naturally alloyed with other metals like copper and palladium, and also mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium(gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia ( a mixture of nitric acid and hydrochloric acid), which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves s...