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) A colourless salt that absorbs moisture from the air and mainly used as a component in fertilizer.

(chemistry)A compound with chemical formula CaWO₄.

Alternative spelling of calcium sulfate

(inorganic chemistry) The calcium salt of sulfuric acid, CaSO₄, the hydrates of which are known as gypsum or plaster of Paris, and the anhydrous mineral form being anhydrite.

(pharmacology) The salt form of the protease inhibitor drug fosamprenavir used in the treatment of HIV infected patients.

(inorganic chemistry) The yellow calcium salt of chromic acid, CaCrO₄

(inorganic chemistry) The calcium salt of phosphoric acid, Ca₃(PO₄)₂, or of several related acids; it is the main mineral of bone

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