Atomic Number: 20
Calcium
Ca
Electrons: 2-8-8-2
Phase: Solid
M.P.: 1112
M.P.: 1757
Occurrence: 0.000199%
Calcium forms 3% of the Earth's crust by mass. It occurs abundantly as
calcium carbonate (limestone), calcium sulphate (gypsum), calcium
fluoride (fluorite) and as calcium chloro- or fluoro-phosphate
(apatite). |