20 Ca

Alkaline earth metal

Calcium

Builds bones and teeth.

See it in the interactive periodic table

Properties of Calcium

Atomic number (Z)
20
Symbol
Ca
Atomic mass
40.078 g/mol
Category
Alkaline earth metal
Group
2
Period
4
Electron configuration
[Ar] 4s²
Electronegativity (Pauling)
1
Atomic radius
194 pm
First ionization energy
590 kJ/mol
Melting point
1115 K (841.9 °C)
Boiling point
1757 K (1483.8 °C)
Density
1.55 g/cm³
Phase at 25 °C
Solid
Discovered
Discovered in 1808
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