CALCIUM

(Ca. 39.9), metallic cal element; S.G. 1.58; light lustrous, ductile, and malleable; oxidizes in air, burns brilliantly, calcium oxide or lime. water with liberation of Abundant in nature combined metallic bases as carbonate, (limestone, chalk marble), Ca3(PO4)2 (minerals apatite, and Occurs di olved in most natural as carbonate or sulphate (calcium phate), causing hardne in bones, shells (carbonate). Metal is obtained decomposing calcium chloride by current.