nitrogen

American  

[nahy-truh-juhn] / ˈnaɪ trə dʒən /

noun

Chemistry.

• nitrogens
  plural

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.

Other Word Forms

Noun Inflected Forms

• nitrogens
  plural

Etymology

Origin of nitrogen

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

Example Sentences

See Examples For:

nitrogen nitrogens

Nitrogen-fixing microorganisms such as M. infernus convert nitrogen into ammonia, but they also play an important role in Earth's carbon cycle.

From Science Daily ● Sep. 19, 2026

Finding the same state in a molybdenum-containing enzyme suggests that all forms of nitrogenase may use a common underlying mechanism to break the nitrogen molecule apart.

From Science Daily ● Sep. 19, 2026

"I think the great significance of these findings, and the tantalizing picture that it promotes, is a great motivation and reason to further examine solid-state nitrogen physics at very low temperatures," Umurhan said.

From Science Daily ● Sep. 17, 2026

Environmental and public health advocates have consistently opposed new smog check waivers, noting they increase exhaust emissions such as nitrogen dioxide that are damaging to human health.

From Los Angeles Times ● Sep. 17, 2026

Similarly, suppose one starts with two boxes, one containing oxygen molecules and the other containing nitrogen molecules.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Serotonin is a tiny molecule, a bibelot built of just 10 carbon atoms, a dozen hydrogens, two nitrogens and a single oxygen.

From New York Times ● May 2, 2011

I can eat starches, and albumens, all right, but I have to keep right away from all carbons and nitrogens.

From Moonbeams from the Larger Lunacy by Stephen Leacock

I observed much and confusing talk of the value of nitrogens, proteids and—when I had reached the ultra-modernists—vitamines.

From One Third Off by Tony Sarg