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

Longer-term fixes would have to address what makes the Reflecting Pool so ideal for algae, such as its depth, darker color and inflow of nitrogen and phosphorus.

From Los Angeles Times • Jun. 20, 2026

CF Industries is the most direct loser because it mainly produces nitrogen fertilizers like urea and ammonia, whose prices would be falling as the Middle East’s supply flow restores following the reopening of Hormuz.

From Barron's • Jun. 15, 2026

Alabama has executed seven people using nitrogen gas since introducing the method in January 2024, one of the few states to do so.

From BBC • Jun. 12, 2026

The French industrial-gases company signed a long-term contract with SK Hynix and will operate a nitrogen unit by late 2027.

From The Wall Street Journal • Jun. 3, 2026

The nitrogen for the fields would no longer be made with the sun’s energy but with fossil fuels.

From "The Omnivore's Dilemma" by Michael Pollan