Molecular nitrogen (${\mathrm{N}}_2$)

Molecular nitrogen is ${\mathrm{N}}_2$, the dominant molecular component of ordinary dry air. Its strong triple bond makes it comparatively resistant to many reactions under ordinary conditions.

Converting it into more reactive nitrogen compounds requires a pathway that activates that bond, as in biological nitrogen fixation or industrial ammonia synthesis. The molecule is homonuclear and has no permanent electric dipole, so its ordinary pure rotational spectrum differs from that of a polar diatomic molecule.