Nitrogen oxide

Nitrogen oxide may refer to any of these chemical compounds:

Nitrous oxide, +1 oxidation state, sweet-smelling anesthetic sometimes called "laughing gas"
Nitric oxide, +2 oxidation state, used in the body as stimulant
Nitrogen dioxide, +4 oxidation state, brown choking gas
Dinitrogen tetroxide, +4 oxidation state, two nitrogen dioxide molecules bonded together
Dinitrogen pentoxide, +5 oxidation state, made from nitric acid