Electronic data		Thermal data		Steric data
Shells: 2,8,8,2 Orbitals: [Ar] 4s2 Electronegativity: 1.0, 1.0 1. Ionization potential: 6.1132 eV 2. Ionization potential: 11.871 eV 3. Ionization potential: 50.908 eV Oxidation states: 2 Electrical conductivity: 0.298 10^6		Melting point: 839 °C Boiling point: 1484 °C Specific heat: 0.63 J/gK Heat of fusion: 8.540 kJ/mol Heat of vaporization: 153.60 kJ/mol Thermal conductivity: 2.00 W/cmK		Atomic radius: 2.23 Å Ionic radius: 1.00 Å () Covalent radius: 1.74 Å Atomic volume: 25.9 cm³/mol Density (293 K): 1.55 g/cm³ Crystal structure: Cubic: Face centered

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
40Ca	96.97	39.9626	0	--	stable	--
41Ca	0	41	7/2	1.03E05y	EC	View
42Ca	0.64	41.9586	0	--	stable	--
43Ca	0.145	42.9588	7/2	--	stable	--
44Ca	2.06	43.9555	0	--	stable	--
45Ca	0	44.956	7/2	162.7d	-	View
46Ca	0.0033	45.9537	0	--	stable	--
47Ca	0	46.954	7/2	4.536d	-	View
48Ca	0.18	47.9525	0	--	stable	--
49Ca	0	49	3/2	8.72m	-	View

Legend

Name origin:	Latin: calx, calcis (lime)
Description:	Fairly hard, silvery-white metal. Fifth most abundant element in the earth's crust (41,500 ppm). Occurs only in compounds.
Discovered by:	Sir Humphrey Davy
Year:	1808
Place:	England
Sources:	Obtained from minerals like chalk, limestone & marble. Pure metal is produced by replacing the calcium in lime (calcium carbonate, CaCO3) with aluminium in hot, low pressure retorts.
Use(s):	Used by many forms of life to make shells and bones. Virtually no use for the pure metal, however two of its compounds are, lime (CaO) and gypsum (CaSO4), are in great demand by a number of industries.