What is Nitrogen?
{{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 oxi