NO2\mathrm{N}_{} \mathrm{O}_{2}NO2
NO\mathrm{N}_{} \mathrm{O}_{}NO
N2O5\mathrm{N}_{2} \mathrm{O}_{5}N2O5
NH3\mathrm{N}_{} \mathrm{H}_{3}NH3
NO3−\mathrm{NO}_{3}^{-}NO3−