Nitrogen is a chemical element with the symbol N2. Elemental nitrogen is a colourless, odourless, tasteless and is as a rule an inert (or static) diatomic gas in standard conditions. Nitrogen constitutes 78.08% of the volume of the earth's atmosphere.
The element nitrogen was discovered by Scottish physician Daniel Rutherford in 1772.
- Nitrogen gas has a variety of applications, including serving as an inert replacement for air where oxidation is undesirable.
- To create a modified atmosphere, pure or mixed with carbon dioxide, to preserve the freshness of packaged or bulk foods (by delaying rancidity and other forms of oxidative damage)
- In ordinary incandescent light bulbs as an inexpensive alternative to argon.
- The production of electronic parts such as transistors, diodes, and integrated circuits.
- Dried and pressurised as a dielectric gas for high voltage equipment.
- The manufacturing of stainless steel.
- Use in military aircraft fuel systems to reduce fire hazards.
- It is used on top of liquid explosives as a safety measure.
- It can be used to fill automotive and aircraft tires because its inertness and lack of moisture or oxidative qualities as opposed to air. It is not necessary for consumer automobiles.
Liquid nitrogen is a cryogenic liquid at atmospheric pressure, it boils at 195.8 °C and when insulated in proper containers such as Dewar flasks, it can be transported with minimal loss through evaporation.
- In food preparation, such as for making ultra-smooth ice cream.
- To preserve tissue samples from surgical excisions for future studies.
- For the cryopreservation of blood, reproductive cells (sperm and egg), and other biological samples and materials.
- As a coolant for vacuum pump traps and in controlled evaporation processes in chemistry.
- To store cells at low temperatures, generally for laboratory work.