Nitrogen is a chemical element wi the symbol N an atomic nummer 7.

Elemental nitrogen is a colourless, odourless, tasteless, an maistly inert diatomic gas at staundart condeetions, constitutin 78.09% bi volume o Yird's atmosphere. The element nitrogen wis discovered as a separable component o air, bi Scots physician Daniel Rutherford, in 1772.^[1] It belangs tae the pnictogen faimily.

Nitrogen is a common element in the universe, estimatit at aboot seivent in tot abundance in the galaxy an the Solar System. It is synthesised bi fusion o carbon an hydrogen in supernovae. Due tae the volatility o elemental nitrogen an its common compoonds wi hydrogen an oxygen, nitrogen is far less common on the rocky planets o the inner Solar System, an it is a relatively rare element on Yird as a hale. Houiver, as on Yird, nitrogen an its compounds occur commonly as gases in the atmospheres o planets an muins that hae atmospheres.

Mony industrially important compoonds, sic as ammonie, nitric acid, organic nitrates (propellants an explosives), an cyanides, contain nitrogen. The extreme strang bond in elemental nitrogen dominates nitrogen chemistry, causin difficulty for baith organisms an industry in convertin the N
₂ intae uissfu compoonds, but at the same time causin release o muckle amoonts o eften uissfu energy whan the compoonds burn, explode, or decay back intae nitrogen gas. Synthetically-produced ammonie an nitrates are key industrial fertilizers an fertilizer nitrates are key pollutants in causin the eutrophication o watter seestems.^[2]

Ootside thair major uisses as fertilizers an energy-stores, nitrogen compounds are versatile organics. Nitrogen is pairt o materials as diverse as Kevlar fabric an cyanoacrylate "super" glue. Nitrogen is a constituent o molecules in every major pharmacological drog class, includin the antibiotics. Mony drugs are mimics or prodrugs o naitural nitrogen-containin signal molecules: for example, the organic nitrates nitroglycerin an nitroprusside control bluid pressur bi bein metabolized tae naitural nitric oxide. Plant alkaloids (eften defence chemicals) contain nitrogen bi defineetion, an sicweys mony notable nitrogen-containin drugs, sic as caffeine an morphine are aither alkaloids or synthetic mimics that act (as mony plant alkaloids dae) upon receptors o ainimal neurotransmitters (for example, seenthetic amphetamines).

Nitrogen occurs in aw organisms, primarily in amino acids (an sicweys proteins) an in the nucleic acids (DNA an RNA).^[3] The human body contains aboot 3% bi wicht o nitrogen, the fowerth maist abundant element in the body efter oxygen, carbon, an hydrogen.^[4] The nitrogen cycle descrieves movement o the element frae the air, intae the biosphere an organic compounds, then back intae the atmosphere.^[5]

• Nitrogen at The Periodic Table o Videos (Varsity o Nottingham)
• Etymology o Nitrogen
• Why heich nitrogen density in explosives? Archived 2013-05-26 at the Wayback Machine
• WebElements.com– Nitrogen
• It's Elemental– Nitrogen Archived 2013-05-20 at the Wayback Machine
• Chemistry in its element podcast (MP3) frae the Ryal Society o Chemistry's Chemistry Warld: Nitrogen
• Schenectady Coonty Community College– Nitrogen Archived 2007-08-22 at the Wayback Machine
• Nitrogen N2 Properties, Uises, Applications
• Haundlin procedures for liquid nitrogen Archived 2007-08-24 at the Wayback Machine