Nitrogen [`naɪ.trə.dʒən] (French nitrogen, Greek a-negation of load and zoe-life) is a chemical element, symbol N (Latin Nitrogenium), at.n. 7, atm 14 0067. Nitrogen is a colorless and odorless gas; density (kg/m3): gas 1.25, liquid 808. Nitrogen is used as an inert medium in the synthesis of ammonia, in various processes and devices, and also as a refrigerant in nitrogen refrigeration units.
Ex. In mining, nitrogen gas is used to keep certain areas safe by preventing explosions and fires.