Nonmetal

Hydrogen

Hydrogen (H) has atomic number 1. PubChem classifies it as nonmetal.

Atomic number

1

Symbol

H

Atomic weight (source value)

1.0080

Electron configuration

1s1

Standard state

Gas

Electronegativity (Pauling)

2.2

Melting point (K)

13.81

Boiling point (K)

20.28

Density (g/cm³)

0.00008988

Oxidation states

+1, -1

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.