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{{Infobox nitrogen}}
'''Nitrogen''' is a [[nonmetal]] [[chemical element]]. The atmosphere contains more than 78 percent of nitrogen. It has the [[chemical symbol]] '''N''' and [[atomic number]] 7. Its stable inside typically contains 14 nucleons (7 [[protons]] and 7 [[neutrons]]). It has 5 electrons in its outer shell. 

==Properties==
[[File:Liquid nitrogen dsc04496.jpg|thumb|Cup of liquid nitrogen]]
Nitrogen is a colorless odorless [[gas]] at normal temperature. It is normally attached to another nitrogen atom, making a nitrogen molecule (N<sub>2</sub>). This bond is very strong. That is why many [[explosive]]s contain nitrogen. The bond is broken when the explosive is made. When it explodes the bond reforms, releasing a lot of energy.

It turns into a liquid at -195.8°C and turns into a [[solid]] at -210°C. If it is compressed, it can be turned into a liquid without making it cold. 

It usually does not combine with other atoms because its strong bond prevents it from reacting. [[Lithium]] is one of the few chemical elements that react with nitrogen without being heated. [[Magnesium]] can burn in nitrogen. Nitrogen also makes blue electric sparks. The blue color is caused by the atoms being excited. When they get normal again, they release light. When nitrogen is excited, it reacts with many things that it does not normally react with.
[[File:Nitrogen-glow.jpg|thumb|Electric spark through a tube filled with nitrogen]]

== Compounds ==
{{see also|Category:Nitrogen compounds}}
Many [[chemical compound]]s that are important for [[Industry|industrial]] purposes contain nitrogen [[ion]]s. These include [[ammonia]], [[nitric acid]], [[nitrate]]s and [[cyanide]]s. Nitrogen comes in several [[oxidation state]]s; -3, -2, -<sup>1</sup>/<sub>3</sub>, +1, +3, +4, and +5. Each of those oxidation states has its set of compounds.

Compounds in the -3 oxidation state are weak [[reducing agent]]s. These include [[ammonia]], [[ammonium]], [[amide]] and [[nitride]]s. [[Amino acid]]s and [[protein]]s contain nitrogen in this oxidation state. [[Hydrazine]], a compound in the -2 oxidation state, is a strong reducing agent. [[Azide]]s contain nitrogen in the -<sup>1</sup>/<sub>3</sub> oxidation state. They are extremely powerful reducing agents, and most are very toxic.

[[Nitrous oxide]] contains nitrogen in the +1 oxidation state. It is used as an [[anesthetic]]. Compounds containing nitrogen in the +2 oxidation state, such as [[nitric oxide]], are reducing agents. +3 oxidation state compounds are strong oxidizing agents and weak reducing agents. [[Nitrite]]s are the most common +3 compounds. Compounds in the +4 oxidation state are strong oxidizing agents. They include [[nitrogen dioxide]] and [[dinitrogen tetroxide]].

Compounds containing nitrogen in the +5 oxidation state are strong oxidizing agents. They are one of the more common groups of nitrogen compounds. They include [[nitric acid]] and [[dinitrogen pentoxide]]. They also include [[nitrate]]s, which are used in [[explosive]]s such as [[dynamite]], [[nitroglycerin]] and [[trinitrotoluene]].

==Occurrence and preparation==
[[Air]] is made up of about 78% nitrogen and about 20.95% [[oxygen]], < 1% argon, and traces of other gasses such as carbon dioxide, and water vapor, among others. It is also in a few [[nitrate]]s in the ground. [[Ammonium]] minerals are rare. Nitrogen is in [[protein]]s.

Pure liquid nitrogen can be made by cooling air. The nitrogen turns into a liquid at a different temperature than the oxygen. It can also be made by heating certain [[chemical compound]]s, such as [[sodium azide]].

==Uses==
[[File:Nitrogen.ogv|thumb|Liquid nitrogen used to freeze a balloon]]
Nitrogen as an element is used to prevent things from reacting with the oxygen in the air. It can be used to fill crisp bags and [[incandescent bulb]]s. It is also used to fill some [[tire]]s. It can be used to make electric components like [[transistor]]s. Liquid nitrogen can be used to freeze things. 

Nitrogen compounds have many uses, such as [[anesthetic]]s ([[nitrous oxide]]), explosives ([[dynamite]]), [[housecleaning|cleaner]]s ([[ammonia]]), and meat ([[protein]]), and planes (fuel).

Oil companies use high pressure nitrogen to help force [[crude oil]] to the surface. 

Nitrogen is also used as a way to relieve body aches. It contributes to the torn bones in your body and helps.<ref>{{Cite book|chapter-url=http://dx.doi.org/10.1007/978-1-4899-6008-5_4|chapter=Touch Me—Feel Me—Feed Me— Kiss Me!|last=Joseph|first=R.|title=The Naked Neuron |date=1993|publisher=Springer US|location=Boston, MA|pages=71–98|doi=10.1007/978-1-4899-6008-5_4 |isbn=978-0-306-44510-1 }}</ref>

==History==
Nitrogen was discovered by Daniel Rutherford in [[1772]], who called it ''noxious gas'' or ''fixed gas''. They discovered that part of air did not burn. It was found that animals died in it. It was known as "azote". Many nitrogen compounds also contain the "azide" or "azine" letters, such as [[hydrazine]].

In 1910, Lord Rayleigh found out that when a spark was passed through nitrogen, it made a reactive form of nitrogen. This nitrogen reacted with many metals and compounds.

==Related pages==
* [[List of common elements]]

==References==
{{reflist}}

{{Periodic Table}}
{{Nitrogen compounds}}

{{authority control}}
[[Category:Nitrogen| ]]