Here are four different ways chemists use to show a molecule of nitrogen. In colored molecule models like these, nitrogen is usually blue.
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Windows to the Universe original artwork by Randy Russell.

Nitrogen

There is more nitrogen gas in the air than any other kind of gas. About 4/5ths of Earth's atmosphere is nitrogen gas! A molecule of nitrogen gas is made up of two nitrogen atoms.

There are other molecules in the atmosphere that have nitrogen atoms in them too, such as nitric oxide (NO) and nitrogen dioxide (NO2). These molecules are air pollutants. They are made in the engines of cars and other places. They also make other kinds of air pollution such as peroxyacetyl nitrate (PAN), a dangerous chemical in smog. They also help make nitric acid. Nitric acid is part of acid rain.

Down on the land, nitrogen atoms are important parts of living creatures, soils, and even rivers. The Nitrogen Cycle explains how nitrogen atoms move around in the environment, including through living things like you and me!

Last modified May 4, 2007 by Lisa Gardiner.

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