The chemical element (Symbol Ca), with an atomic number 20. It is a soft, silvery-white alkaline earth metal which occurs naturally as carbonate in limestone and as silicate in many rocks.

plural of calcium

(inorganic chemistry) An inorganic compound and a white insoluble solid, CaF₂, occurring as fluorite.

(inorganic chemistry) A colourless or white inorganic compound, CaCO₃, occurring as chalk, limestone, marble etc; reacts with acids to liberate carbon dioxide.

(chemistry) the calcium salt of sorbic acid

(chemistry) the calcium salt of benzoic acid

(chemistry) the calcium salt of formic acid; used in the scrubbing of flue gases, and as a food preservative

(inorganic chemistry) A black, solid, of formula CaC₂, manufactured from lime and carbon at high temperatures; reacts with water to form acetylene.

(inorganic chemistry) A soft, white powder, Ca(OH)₂, obtained by the action of water on calcium oxide; slaked lime.

(inorganic chemistry) A white powderous substance, CaO, normally made by heating calcium carbonate.