Calcium

Name: Calcium
Symbol: Ca
Atomic Number: 20
Atomic Mass: 40.078 amu
Melting Point: 839.0 °C (1112.15 K, 1542.2 °F)
Boiling Point: 1484.0 °C (1757.15 K, 2703.2 °F)
Number of Protons/Electrons: 20
Number of Neutrons: 20
Classification:Alkaline Earth
Crystal Structure: Cubic
Density @ 293 K: 1.55 g/cm3
Color: Silvery

Date of Discovery: 1808
Discoverer: Sir Humphrey Davy
Name Origin: From the latin word calcis (lime)
Uses: life forms for bones and shells
Obtained From: chalk, limestone, marble. 3.5% of crust