nitrogen

American  

[nahy-truh-juhn] / ˈnaɪ trə dʒən /

noun

Chemistry.

1. a colorless, odorless, gaseous element that constitutes about four-fifths of the volume of the atmosphere and is present in combined form in animal and vegetable tissues, especially in proteins: used chiefly in the manufacture of ammonia, nitric acid, cyanide, explosives, fertilizer, dyes, as a cooling agent, etc. N; 14.0067; 7; density: 1.2506 grams/liter at 0°C and 760 millimeters pressure.

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nitrogen British  

/ ˈnaɪtrədʒən /

noun

1. 1. a colourless odourless relatively unreactive gaseous element that forms 78 per cent (by volume) of the air, occurs in many compounds, and is an essential constituent of proteins and nucleic acids: used in the manufacture of ammonia and other chemicals and as a refrigerant. Symbol: N; atomic no: 7; atomic wt: 14.00674; valency: 3 or 5; density: 1/ 2506 kg/m³; melting pt: –210.00°C; boiling pt: –195.8°C

   2. ( as modifier )

      nitrogen cycle

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nitrogen Scientific  

/ nī′trə-jən /

1. A nonmetallic element that makes up about 78 percent of the atmosphere by volume, occurring as a colorless, odorless gas. It is a component of all proteins, making it essential for life, and it is also found in various minerals. Nitrogen is used to make ammonia, nitric acid, TNT, and fertilizers. Atomic number 7; atomic weight 14.0067; melting point −209.86°C; boiling point −195.8°C; valence 3, 5.

2. See Periodic Table See Note at oxygen

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nitrogen Cultural  

1. A chemical element that makes up about four-fifths of the atmosphere of the Earth. Its symbol is N.

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Discover More

Like carbon, nitrogen is a necessary element in the tissues of living things.

Etymology

Origin of nitrogen

First recorded in 1785–95; from French nitrogène; nitro-, -gen

Example Sentences

They use the nitrogen and other nutrients in wee to produce fertiliser on site, easing the burden on sewage systems as the events run and reducing chemical use.

From BBC • Apr. 2, 2026

The third region contains organic compounds that include nitrogen, an element that plays a key role in biological molecules such as amino acids.

From Science Daily • Mar. 31, 2026

Although the U.S. has a robust fertilizer manufacturing industry, the country still relies on nitrogen and phosphate imports to meet demand, Milam adds.

From Barron's • Mar. 29, 2026

The rise in costs are bad enough, but now there are fears that a key liquid fertilizer, UAN-32 — which contains three forms of nitrogen, including liquid urea — could be in short supply.

From Los Angeles Times • Mar. 29, 2026

And while the chickens are nibbling on the grasses, they add a few thousand pounds of nitrogen to the pasture with their own droppings— and produce several thousand rich and tasty eggs.

From "The Omnivore's Dilemma" by Michael Pollan