Nítrójìn: Ìyàtọ̀ láàrin àwọn àtúnyẹ̀wò

{{Infobox nitrogen}}

 

Nítrójìn jẹ́ ẹ́límẹ̀ntì tó wọ́pọ̀ nínú àgbálá-ayé, estimated at about seventh in total abundance in our [[Milky Way|galaxy]] and the [[Solar System]]. It is synthesised by fusion of carbon and hydrogen in supernovas. Due to the volatility of elemental nitrogen and its common compounds with hydrogen and oxygen, nitrogen is far less common on the rocky planets of the inner Solar System, and it is a relatively rare element on Earth as a whole. However, as on Earth, nitrogen and its compounds occur commonly as gases in the atmospheres of planets and moons that have atmospheres.

 

Nitrogen occurs in all organisms, primarily in [[amino acid]]s (and thus [[proteins]]) and also in the [[nucleic acid]]s ([[DNA]] and [[RNA]]). The human body contains about 3% by weight of nitrogen, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The [[nitrogen cycle]] describes movement of the element from the air into the [[biosphere]] and organic compounds, then back into the atmosphere.

Nitrogen is formally considered to have been discovered by Scottish physician [[Daniel Rutherford]] in 1772, who called it ''noxious air'' or ''fixed air''.<ref>{{Cite book|url=http://books.google.com/?id=yS_m3PrVbpgC&pg=PR15|page=15|title=Elements of chemistry, in a new systematic order: containing all the modern discoveries|author=Lavoisier, Antoine Laurent|authorlink=Antoine Lavoisier|publisher=Courier Dover Publications|year=1965|isbn=0-486-64624-6}}</ref> The fact that there was constituent of air that does not support [[combustion]] was clear to Rutherford. Nitrogen was also studied at about the same time by [[Carl Wilhelm Scheele]], [[Henry Cavendish]], and [[Joseph Priestley]], who referred to it as ''burnt air'' or ''[[Phlogiston theory|phlogisticated air]]''. Nitrogen gas was [[inert]] enough that [[Antoine Lavoisier]] referred to it as "[[wikt:mephitic air|mephitic air]]" or ''azote'', from the Greek word {{lang|el|ἄζωτος}} (''azotos'') meaning "lifeless".<ref>''Elements of Chemistry'', trans. Robert Kerr (Edinburgh, 1790; New York: Dover, 1965), 52.</ref> In it, animals died and flames were extinguished. Lavoisier's name for nitrogen is used in many languages (French, Italian, Polish, Russian, Albanian, etc.) and still remains in English in the common names of many compounds, such as hydrazine and compounds of the [[azide]] ion.