Electronic Structure and Bonding Capacity of Oxygen

Oxygen belongs to group 16 of the periodic table. It has 8 protons and 8 neutrons in its nucleus.

The electronic configuration of oxygen is: ₈O = 1s², 2s², 2p⁴.

In all of its compounds, oxygen assumes a negative oxidation state as is expected from the two half-filled outer orbitals. When these orbitals are filled by electron transfer, the oxide ion O²⁻ is created. In peroxides (species containing the ion O₂²⁻), each oxygen assumes a charge of −1. Hence, oxygen shows an oxidation state of -2 in most of its compounds and -1 in peroxides.