Nitrogen

Nitrogen

Tim Wright

Nitrogen was isolated by the British physician Daniel Rutherford in 1772 and recognized as an elemental gas by the French chemist Antoine Laurent Lavoisier about 1776.

Properties

Nitrogen is a colorless, odorless, tasteless, nontoxic gas. It can be condensed into a colorless liquid, which can in turn be compressed into a colorless, crystalline solid. Nitrogen exists in two natural forms of isotopes, and four radioactive isotopes have been artificially prepared. Nitrogen melts at -210.01° C (-346.02° F), boils at -195.79° C (-320.42° F), and has a density of 1.251 g/liter at 0° C (32° F). The atomic weight of nitrogen is 14.007.

Nitrogen is obtained from the atmosphere by passing air over heated copper or iron. The oxygen is removed from the air, leaving nitrogen mixed with some inert gases. Pure nitrogen is obtained by partial evaporation of liquid air because liquid nitrogen has a lower boiling point than liquid oxygen, the nitrogen evaporates off first and can be collected.

Nitrogen composes about four-fifths (78.03 percent) 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 nitrogen from the atmosphere 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 component of animal tissue. The element occurs in t...

Nitrogen

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