nitrogenparticularly

Nitrogen is a chemical element with the symbol N and atomic number 7. It is most commonly found as the diatomic molecule N2, which makes up about 78 percent of Earth's atmosphere. N2 is characterized by a strong triple bond, making it relatively inert at ambient temperatures and pressures.

In biology and ecology, nitrogen is essential for life because it is a primary component of amino acids, nucleic acids, and many biomolecules. Although abundant in the atmosphere, most organisms cannot use N2 directly. Nitrogen must be fixed into reactive forms such as ammonia (NH3) or nitrate (NO3−) by biological organisms (nitrogen-fixing bacteria and cyanobacteria) or industrial processes (Haber-Bosch synthesis). Plants absorb nitrate or ammonium and incorporate nitrogen into organic molecules; animals obtain nitrogen by consuming plants or other animals. The nitrogen cycle encompasses fixation, assimilation, mineralization, nitrification, and denitrification, returning nitrogen to the atmosphere as N2 or N2O.

Isotopes: The stable isotopes N-14 and N-15 are used in scientific studies, including tracing nitrogen pathways and dating processes.

Industrial and technological uses: The production of fertilizers, explosives, and many chemicals relies on nitrogen compounds such as ammonia, urea, nitric acid, and ammonium salts. Nitrogen is also used as an inert shielding gas in welding and in cryogenic applications and electronics manufacturing.

Environmental considerations and safety: Excess nitrogen from fertilizers promotes eutrophication and algal blooms, while nitrous oxide is a greenhouse gas and ozone-depleting. Nitrogen gas is generally non-toxic but asphyxiating in enclosed spaces at high concentrations; many nitrogen compounds are caustic, oxidizing, or toxic and require proper handling and storage in pressure vessels or cryogenic systems.