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Ca - Calcium

Calcium

 Calcium 
Ca
Atomic Number: 20
Atomic Weight: 40.078
Element Type: Alkali Earth Metal
Crystal Structure: Cubic Face Centered
Melting Point: 842.0°C = 1547.6°F = 1115.15 K
Boiling Point: 1484.0°C = 2703.2°F = 1757.15 K
Critical Temp: °C = °F = K
Atomic Radius: 2.23 Å (Å = Angstrom = 10-10 m)
Covalent Radius: 1.74 Å
Electronegativity: 1.0

History

(L. calx, lime) Though lime was prepared by the Romans in the first century under thename calx, the metal was not discovered until 1808. After learning that Berzelius andPontin prepared calcium amalgam by electrolyzing lime in mercury, Davy was able to isolatethe impure metal.


Sources

Calcium is a metallic element, fifth in abundance in the earth's crust, of which ifforms more than 3%. It is an essential constituent of leaves, bones, teeth, and shells.Never found in nature uncombined, it occurs abundantly as limestone, gypsum, and fluorite.Apatite is the fluorophosphate or chlorophosphate of calcium.



Science Quote

'When I examine myself and my methods of thought, I come to the conclusion that the gift of fantasy has meant more to me than my talent for absorbing positive knowledge.'

Albert Einstein
(1879-1955)


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