Symbol Ca Atomic radius: pm 197 Fusion: kJ/Mole 8.54
Name Calcium Ionic radius: pm (+2)100 Boiling point: C 1484
Atomic number 20 Electron affinity 0.04 Melting point: C 842
Atomic weight 40.08 1st  ion potential 6.11 Specific Heat Cap: J/(g K) 0.65
Classification Alk earth metal Natural form Solid Thermal Cond: W/(cm K) 2.01
Configuration [Ar]4s2 Crystal structure FCC Electrical Cond 0.298
Oxidation states 2 Density 1.54 Abundance: mg/kg-crust 41,500
Electronegativity 1.00 Vaporization: kJ/Mole 150.0    
Although calcium was extensively used by the ancients as the compound lime, the metal itself was first isolated in 1808 by Sir Humphrey Davy. Uses - lime, cement, reducing agent for preparation of some metals