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

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;
certain bacteria in the soil convert atmospheric nitrogen into a form,
such as nitrate, that can be absorbed by
plants, a process called nitrogen fixation. Nitrogen in the form of
protein is an important constituent of
animal tissue. The element occurs in the combined state in minerals, of
which saltpeter (KNO ) and Chile
saltpeter (NaNO ) are commercially important products.

Nitrogen combines with other elements only at very high
temperatures of pressures. It is
converted to an active form by passing through an electronic discharge
at low pressure. The nitrogen so
produced is very active, combining with alkali metals to form azides;
with the vapor of zinc, mercury
cadmium, and arsenic to form nitrides; and with many hydrocarbons to
form hydrocyanic acid and
cyanides, also known as nitriles. Activated nitrogen returns to
ordinary nitrogen in about one minute.

In the combined state nitrogen takes part in many reactions; it
forms so many compounds that a
systematic scheme of compounds containing nitrogen in place of oxygen
was created by the American
chemist Edward Franklin. In compounds nitrogen exists in all the
valence states between -3 and +5.
Ammonia, hydrazine, and hydroxylamine represent compounds in which the
valence of nitrogen is -3, -2,
and -1, respectively. Oxides of nitrogen represent nitrogen in all the
positive valence states.

Most of the nitrogen used in the chemical industry is obtained
by the fractional distillation of
liquid air. It is then used to synthesize ammonia. From ammonia
produced in this manner, a wide variety
of important chemical products are prepared, including fertilizers,
nitric acid, urea, hydrazine, and amines.
In addition, an ammonia compound is used in the preparation of nitrous
oxide (N 0) a colorless gas
popularly known as laughing gas. Mixed with oxygen, nitrous oxide is
used as an anesthetic for some
types of surgery.

Used as a coolant, liquid nitrogen has found widespread
application in the field of cryogenics.
With the recent advent of ceramic materials that become superconductive
at the boiling point of nitrogen,
the use of nitrogen as a coolant is increasing.

In conclusion, it seems as if Nitrogen is very helpful in the
modern world. It is used in dentists
office\'s to using it for industrial applications. Without this element
the world would be a little different in
some fields.