Nitrogen is a chemical element with symbol N and atomic number 7.
- Nitrogen is commonly used during sample preparation in chemical analysis. It is used to concentrate and reduce the volume of liquid samples. Directing a pressurised stream of nitrogen gas perpendicular to the surface of the liquid causes the solvent to evaporate while leaving the solute(s) and un-evaporated solvent behind.
- Nitrogen can be used as a replacement, or in combination with, carbon dioxide to pressurise kegs of some beers, particularly stouts and British ales, due to the smaller bubbles it produces, which makes the dispensed beer smoother and headier. A pressure-sensitive nitrogen capsule known commonly as a “widget” allows nitrogen-charged beers to be packaged in cans and bottles.
- Nitrogen tanks are also replacing carbon dioxide as the main power source for paintball guns. Nitrogen must be kept at higher pressure than CO2, making N2 tanks heavier and more expensive. Nitrogen gas has become the inert gas of choice for inert gas asphyxiation, and is under consideration as a replacement for lethal injection in Oklahoma. Nitrogen gas, formed from the decomposition of sodium azide, is used for the inflation of airbags.
Normal growth, cell replacement and tissue repair all require nitrogen for production of new cells. Although nitrogen is abundant in the environment, humans cannot directly use it from the air or soil, but instead depend on microbes and green plants to convert it into form our bodies can use.
Your body is constantly recycling nitrogen from amino acids. If amino acids are not used for protein synthesis, they can be broken into components, including nitrogen, to produce energy.
Nitrogen can also be used to make other types of compounds that aren’t proteins, such as the heme in hemoglobin, which carries oxygen in red blood cells.
When inhaled at high partial pressures (more than about 4 bar, encountered at depths below about 30 m in scuba diving), nitrogen is an anesthetic agent, causing nitrogen narcosis, a temporary state of mental impairment similar to nitrous oxide intoxication.
Nitrogen dissolves in the blood and body fats. Rapid decompression (as when divers ascend too quickly or astronauts decompress too quickly from cabin pressure to spacesuit pressure) can lead to a potentially fatal condition called decompression sickness (formerly known as caisson sickness or the bends), when nitrogen bubbles form in the bloodstream, nerves, joints, and other sensitive or vital areas. Bubbles from other “inert” gases (gases other than carbon dioxide and oxygen) cause the same effects, so replacement of nitrogen in breathing gases may prevent nitrogen narcosis, but does not prevent decompression sickness.
Source: LiveStrong, http://www.livestrong.com/article/500133-why-does-our-body-need-nitrogen/