# Oxidation state of N in NO from resonance

I know from a textbook that nitrogen has an oxidation state of +II in NO, and this is easily verified if O is assigned -II.

However, if one looks at the resonance structure and assigns covalent electrons to the partner with higher electronegativity, then, for the resonance structure with the radical on the N, N has an oxidation state of +II - but for the resonance structure with the radical on the O, N has an oxidation state of +I, and their average should be +1.5?

  +V                    +IV
[ |N. = |O|   <-->  (-) |N| = O|. (+)]

• OK so you just spotted one of the weaknesses in the oxidation states model - because that it just what it is, a model. It is useful for understanding what is going on, but does not fully describe all circumstances. – Waylander Nov 5 '18 at 21:52