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20 - Calcium alkaline earth metal

Discovered by Humphry Davy in 1808

Calcium

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.

H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
57-71 La-Lu Lanthanides
89-103 Ac-Lr Actinides
Shell Electrons Orbitals
1 2 2 in 1s
2 8 2 in 2s + 6 in 2p
3 8 2 in 3s + 6 in 3p
4 2 2 in 4s
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
40.1  u Atomic Mass
2.2  Å Atomic Radius
1.76k  K Boiling Point
1.76  Å Covalent Radius
1.55  g/cm³ Density
2.37 Electron Affinity
1 Electronegativity
6.11  eV First Ionization Energy
1.11k  K Melting Point
4 Number of Shells
2 Electron Valency
20 Atomic Number
2, 8, 8, 2 Electron Shell Occupations
0.647  J/(g K) Specific Heat