Key information
Atomic number: 
20
Atomic weight: 
40.08
Density: 
1550 kg/m³
Boiling point: 
1713.16° K
Melting point: 
1111.16° K
Heat vapour: 
153.85 kJ/mol
Heat fusion: 
8.79 kJ/mol
Thermal conductivity: 
21.8 W/m/K
Specific heat capacity: 
125.63 J/kg/K

Calcium is the fifth element in abundance in the earth's crust, of which it forms more than 3%. It occurs as Limestone, Gypsum and Fluorite.

Calcium reacts with water to create an alkaline solution

2H2O Ca = Ca(OH)2 (calcium hydroxide) + H2

Calcium is found in drinking water where it adds to the hardness of the water. Calcium ions create scale in bathrooms and kitchens, and in appliances such as kettles.

Electron Shell: 
Amazon Books
Image of The Last Sorcerers: The Path from Alchemy to the Periodic Table
Author: National Academy of Sciences, Richard Morris
Publisher: Henry (Joseph) Press (2003)
Binding: Hardcover, 294 pages