Which compounds have the highest nitrogen oxidation state?

The oxidation state is called the charge that an atom acquires as a result of the recoil or attachment of electrons.
Nitrogen or nitrogen is an element of group 5, so it does not have enough electrons until the outer level of 3 electrons is completed, taking them away, it acquires an oxidation state of -3. At the same time, at the external energy level, nitrogen has 5 electrons, giving them away, it can acquire the maximum oxidation state of +5. Nitrogen has this oxidation state in nitric acid (HNO3) and its salts, which are called nitrates.