|a. 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|
|b. (as modifier): nitrogen cycle|
nitrogen ni·tro·gen (nī'trə-jən)
A nonmetallic element that constitutes nearly four fifths of the air by volume, occurring as a colorless, odorless, almost inert diatomic gas, N2, in various minerals and in all proteins. Atomic number 7; atomic weight 14.0067; melting point -210.00°C; boiling point -195.8°C; valence 3, 5.
|nitrogen (nī'trə-jən) Pronunciation Key
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. See Periodic Table. See Note at oxygen.