Nitrogen, symbol N, gaseous element that makes up the largest portion of the earth's atmosphere.
The atomic number of nitrogen is 7. Nitrogen is in group 15 (or Va) of the periodic table.
Nitrogen was discovered by the British physician Daniel Rutherford in 1772 and recognized as an
elemental gas by the French chemist, Antoine Laurent Lavoiser about 1776.
Nitrogen is a colorless, odorless tasteless, nontoxic gas. It can be condensed into a colorless
liquid, which can be compressed into a colorless, crystalline solid. Nitrogen exists in two natural forms,
and four radioactive forms (artificial). Nitrogen melts at -210.01 degrees C, (-349.02 F), boils at -195.79 C
(320.42 F), and has a density of 1.251 g/liter at 0 C (32 F) and 1 atmosphere pressure. The atomic weight
of nitrogen is 14.007.
Nitrogen is obtained from the atmosphere by passing air over heated copper of iron. The oxygen
is removed from the air, leaving nitrogen mixed with inert gases. Pure nitrogen is obtained by fractional
distillation of liquid air; because liquid nitrogen has a lower boiling point than liquid oxygen, the nitrogen
distills of first an can be collected.
Nitrogen compresses about 4/5ths by volume of the atmosphere. Nitrogen is inert and serves as a
diluent for oxygen in burning and respiration processes. It is an important element in plant nutrition;