| 释义 |
ni·tro·gen
\ˈnī.trə̇jə̇n, -rēj-\ noun
(-s)
Etymology: French nitrogène, from nitr- + gène -gen
a common nonmetallic element that in the free form is normally a colorless odorless tasteless insoluble inert diatomic gas comprising 78 percent of the atmosphere by volume, obtained industrially by fractional distillation of liquid air, and used chiefly as an inert atmosphere (as in industrial processes) and that in the combined form has a wide range of valences (as from -3 in ammonia to +5 in nitric acid and nitrates) and is a constituent of biologically important compounds (as proteins, nucleic acids, alkaloids) and hence of all living cells as well as of industrially important substances (as cyanides, fertilizers, dyes, antibiotics) — symbol N; see element table, nitrogen cycle, nitrogen fixation |