8 O 15.999

Oxygen

diatomic nonmetal

Properties

Atomic number
8
Atomic mass
15.999 u
Category
diatomic nonmetal
Group
16
Period
2
Block
p-block
State (room temp)
Gas
Outer-shell electrons
6
Electronegativity
3.44 (Pauling)
Density
Melting point
-218.79 °C
Boiling point
-182.96 °C

Electron configuration

1s² 2s² 2p⁴

Noble-gas shorthand: [He] 2s² 2p⁴

Electrons per shell: 2, 6 — that's 6 in the outermost shell.

See how electron configuration is built →

O
Bohr model — outer-shell electrons in blue

About Oxygen

Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds (notably oxides) with most elements. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.