NO. 008Reactive Nonmetal

O

Oxygen

Oxygen supports combustion and is vital for respiration.

Crystal Structure

Orthorhombic

Atomic Mass15.999 u

Density0.001429 g/cm³

Melting Point54.36 K

Boiling Point90.19 K

Atomic Radius48 pm

Electronegativity3.44

Ionization Energy1314 kJ/mol

Electron Affinity141 kJ/mol

Bonding TypeCovalent

Oxidation States-2

Acid/BaseNeutral

ReactivityHigh

Electron Configuration

[He] 2s2 2p4

Discovered ByJoseph Priestley

Year1774

Known Isotopes

Oxygen-16Oxygen-17Oxygen-18