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How do lightning and ultraviolet radiation fix small amounts of atmospheric nitrogen?

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Difference in molecular structure between ammonia/amines and quaternary ammonium ions — ammonia Ammonia and amines have a slightly flattened trigonal pyramidal shape with a lone pair of electrons above the nitrogen. In quaternary ammonium ions, this area is occupied by a fourth substituent.

In nature, lightning and ultraviolet radiation fix small amounts of atmospheric nitrogen by converting it into nitric oxide.1

It is important to clarify that while these abiotic processes are a form of nitrogen fixation, they do not directly produce ammonia in the same way that biological processes or the Haber-Bosch process do. Instead, lightning and ultraviolet rays provide the energy necessary to break the strong bonds of atmospheric nitrogen gas, allowing it to combine with oxygen to form nitric oxide. This compound can subsequently be converted into nitrates, which are then utilized by plants.213

While these abiotic mechanisms contribute to the nitrogen cycle, they account for a much smaller portion of total nitrogen fixation compared to the work performed by nitrogen-fixing bacteria and blue-green algae, which are responsible for more than 90 percent of the process.143