Nitrogen fixation is a process in which nitrogen (N₂) in the atmosphere is converted into ammonium (NH₄⁺) or nitrogen dioxide , for example. Atmospheric nitrogen or molecular nitrogen (N₂) is relatively inert: it does not easily react with other chemicals to form new compounds. The fixation process frees up the nitrogen atoms from their triply bonded diatomic form, N=N, to be used in other ways.