Alkaline earth metal

Calcium

Calcium (Ca) has atomic number 20. PubChem classifies it as alkaline earth metal.

Atomic number

20

Symbol

Ca

Atomic weight (source value)

40.08

Electron configuration

[Ar]4s2

Standard state

Solid

Electronegativity (Pauling)

1

Melting point (K)

1115

Boiling point (K)

1757

Density (g/cm³)

1.54

Oxidation states

+2

Understanding this entry

Atomic number is the number of protons in the nucleus. Properties are reference values and may depend on conditions and measurement conventions. An atomic weight is not the mass of every isotope. For elements without a standard atomic weight, a source may report an isotope mass number. Blank source values are shown as unavailable rather than estimated.

Further reading and reference: NIH PubChem source dataset ↗. Values and educational summaries are not a substitute for specialised advice.