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Calcium
CalciumCa Electron 1 Electron 2 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 1 Electron 2

Calcium is a chemical element with symbol Ca and atomic number 20. Calcium is a soft gray alkaline earth metal, fifth-most-abundant element by mass in the Earth's crust. The ion Ca2+ is also the fifth-most-abundant dissolved ion in seawater by both molarity and mass, after sodium, chloride, magnesium, and sulfate.

20 Atomic Number
40.08  u Atomic Mass
1112.15  K Melting Point
1757  K Boiling Point
1.55  g/cm³ Density
2.2  Å Atomic Radius
1.76  Å Covalent Radius
1 Electronegativity
6.11  eV First Ionization Energy
2.37 Electron Affinity
4 Number of Shells
2 Electron Valency
2, 8, 8, 2 Electron Shell Occupations
0.65  J/g Specific Heat