All oxides of Nitrogen are common pollutants except _.

Explanation

Nitrogen oxides like NO and NO2 (collectively known as NOx) and nitrous oxide (N2O) are significant air pollutants and/or greenhouse gases. Dinitrogen pentoxide (N2O5) is a highly reactive and unstable solid that readily reacts with water to form nitric acid and is not typically considered a primary atmospheric pollutant itself.