* Nitrogen monoxide (NO): This is the simplest nitrogen oxide, and it has the same empirical formula as all the other nitrogen oxides listed below.

* Dinitrogen dioxide (N₂O₂): This is a very unstable compound, but it has the same empirical formula as NO.

* Dinitrogen tetroxide (N₂O₄): This is a dimer of NO₂ and is in equilibrium with NO₂. Although it has a different molecular formula, its empirical formula is still NO.

Therefore, all three of these nitrogen oxides share the same empirical formula, NO.