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nitrogen 音标拼音: [n'ɑɪtrədʒən] n. U氮 U氮 nitrogen n 1: a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living tissues [synonym: {nitrogen}, {N}, {atomic number 7}] Nitrogen \Ni`tro*gen\ (n[imac]"tr[-o]*j[e^]n), n. [L. nitrum natron -gen: cf. F. nitrog[`e]ne. See {Niter}.] (Chem.) A colorless nonmetallic element of atomic number 7, tasteless and odorless, comprising four fifths of the atmosphere by volume in the form of molecular nitrogen ({N2}). It is chemically very inert in the free state, and as such is incapable of supporting life (hence the name {azote} still used by French chemists); but it forms many important compounds, such as ammonia, nitric acid, the cyanides, etc, and is a constituent of all organized living tissues, animal or vegetable. Symbol N. Atomic weight 14.007. It was formerly regarded as a permanent noncondensible gas, but was liquefied in 1877 by Cailletet of Paris, and Pictet of Geneva, and boils at -195.8 [deg] C at atmospheric pressure. Liquid nitrogen is used as a refrigerant to store delicate materials, such as bacteria, cells, and other biological materials. [1913 Webster PJC] 46 Moby Thesaurus words for "nitrogen": acetylene, ammonia, argon, asphyxiating gas, butane, carbon dioxide, carbon monoxide, castor-bean meal, chlorine, coal gas, commercial fertilizer, compost, dressing, dung, enrichener, ethane, ether, ethylene, fertilizer, fluorine, formaldehyde, guano, helium, hydrogen, illuminating gas, krypton, lewisite, manure, marsh gas, methane, muck, mustard gas, natural gas, neon, night soil, nitrate, organic fertilizer, oxygen, ozone, phosphate, poison gas, propane, radon, sewer gas, superphosphate, xenon nitrogen Symbol: N Atomic number: 7 Atomic weight: 14.0067 Colourless, gaseous element which belongs to group 15 of the periodic table. Constitutes ~78% of the atmosphere and is an essential part of the ecosystem. Nitrogen for industrial purposes is acquired by the fractional distillation of liquid air. Chemically inactive, reactive generally only at high temperatures or in electrical discharges. It was discovered in 1772 by D. Rutherford.
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