Nitrogen, a common element in the universe, is a colourless and odourless diatomic gas. The gas is mostly used as an inert atmosphere whenever the oxygen in the air would pose a fire, explosion, or oxidising hazard.
It may be used as a modified atmosphere, to nitrogenate and preserve the freshness of packaged or bulk foods. The gas is an excellent replacement for carbon dioxide to pressurise kegs of beers due to the smaller bubbles it produces, leading to smoother and headier drink. Being an inert gas, it can be used as an inexpensive alternate to argon in incandescent light bulbs. Furthermore, Nitrogen is used on fire suppression and inerting systems, to inflate tyres and in numerous manufacturing processes. Another common use of Nitrogen is in cryogenics and vacuum pump systems.