A1.2.2 Nitrogen


Nitrogen is a chemical element, with the chemical symbol of N. In its natural state it is a gas (N2) and it makes up approximately 78% of the earth’s atmosphere.

Nitrogen is essential for life forms, but most organisms cannot use atmospheric nitrogen. They are unable to fix atmospheric nitrogen (take it from the environment and use it). And therefore have to obtain nitrogen as an essential nutrient from other sources. This is usually done by taking the nitrogen from compounds it is contained within, such as nitrate ions, urea and ammonia.

Nitrogen occurs naturally in several minerals, but most of these are relatively rare. This partly because they are readily soluble in water (they dissolve). Nitrogen is present in all living organisms, for example, it is found in proteins. It is a large component of animal waste, as it is contained within urea, uric acid and ammonia.

Industrial Applications:

Nitrogen gas has a number of uses in industry. It is used to preserve the freshness of packaged goods (as an alternative to oxygen that will allow oxidation), as a cheaper alternative to argon in light bulbs and in the production of stainless steel.

Liquid nitrogen is used as a refrigerant. For example, in medical establishments it is used for the storage of reproductive cells and biological samples.