Nitrogen

{iiif -tro-jeii) [Arab., nitrun, natron; -■n-var, to produce]. Symbol N; atomic weight 14; quantivalence I, ill, v. A nonmetallic element existing free in the atmosphere, of which it constitutes about 77 per cent, by weight. It is a colorle , odorle gas, incapable of sustaining life. Chemically it is very inert, and combines directly with but few elements. It is an important constituent of all animal and vegetal ti ues. s- With hydrogen it combines to form ammonia, from which a multitude of important compounds are derived. It forms several oxygen - compounds: Nitrogen monoxid, N20; nitrogen dioxid, NO; nitrogen trioxid, N203; nitrogen tetroxid, N02; nitrogen pentox id, N205. The oxids combine with water to form acids. With the halogens nitrogen forms very explosive compounds; nearly all explosive substances are compounds of nitrogen. 449