SymbolCa
Latin nameCalcium
Atomic number20
Period4
Element categoryAlkaline earth metals
Relative atomic mass40.078
GroupII.A
Electronegativity
1.0
Oxidation numbers
2
Electron configuration
1s2 2s2 2p6 3s2 3p6 4s2
Density [g/cm3]
1.55
State
Solid
Melting point [°C]
839
Boiling point [°C]
1484
Thermal conductivity [W m-1K-1]
200
Heat capacity [J K-1g-1]
0.647
Discovery
1808
Hardness [Mohs scale]
1.5-2
Brinell hardness [MPa]
167
Young's modulus [GPa]
20
Electrical conductivity [S m-1]
3.13 · 107
Shear modulus [GPa]
7.4
1.st ionization energy [eV]
6.1132
2.nd ionization energy [eV]
11.871
3.rd ionization energy [eV]
50.908
Stable isotopes
6
Unstable isotopes
8