Gold. Gold is a chemical element; it has the symbol Au and the atomic number 79. In its pure form, it is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal.
Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactive chemical elements, being the second-lowest in the reactivity series.
It is solid under standard conditions. Gold often occurs in free elemental, as nuggets or grains, in rocks, veins, and alluvial deposits.
It occurs in a solid solution series with the native element silver, naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium.
Gold is resistant to most acids, though it does dissolve in aqua regia, forming a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid alone, which dissolves silver and base metals, a property long used to refine gold and confirm the presence of gold in metallic substances, giving rise to the term 'acid test'. Gold dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold also dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute, this is not a chemical reaction. A relatively rare element, gold is a precious metal that has been used for coinage, jewelry
Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactive chemical elements, being the second-lowest in the reactivity series.
It is solid under standard conditions. Gold often occurs in free elemental, as nuggets or grains, in rocks, veins, and alluvial deposits.
It occurs in a solid solution series with the native element silver, naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium.
Gold is resistant to most acids, though it does dissolve in aqua regia, forming a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid alone, which dissolves silver and base metals, a property long used to refine gold and confirm the presence of gold in metallic substances, giving rise to the term 'acid test'. Gold dissolves in alkaline solutions of cyanide, which are used in mining and electroplating. Gold also dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute, this is not a chemical reaction. A relatively rare element, gold is a precious metal that has been used for coinage, jewelry
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