This page explains how smog is formed from nitrogen compounds (NOx ) produced during high-temperature combustion in cars. Although nitrogen gas (N2) is inert due to its strong trip...This page explains how smog is formed from nitrogen compounds (NOx ) produced during high-temperature combustion in cars. Although nitrogen gas (N2) is inert due to its strong triple bonds, it can become reactive with sufficient energy. The concept of bond energy indicates that higher energy correlates with greater stability and less reactivity. Bacteria play a crucial role in converting nitrogen into usable forms for plants and animals.