ni·tro·gen /ˈnaɪtrəʤən/
 U氮


 ni·tro·gen /ˈnaɪtrəʤən/ 名詞
 氮


 Ni·tro·gen n.  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 ° C at atmospheric pressure.  Liquid nitrogen is used as a refrigerant to store delicate materials, such as bacteria, cells, and other biological materials.

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 nitrogen
      n : 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 [syn: N, atomic number 7]


 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.