Chemical symbol: N
Available supply: With about a 78 per cent share, it is the largest component of air; its share of the combined mass of the atmosphere and the outer layer of the Earth’s crust is 0.03 per cent
Boiling point: -196 °C
Freezing point: - 210 °C
Chemical properties: The odourless and tasteless molecular nitrogen condenses to a colourless liquid. It is extremely inert; barely soluble in water and non-flammable.
As an essential component of amino acids, nitrogen is a basic element of all life. Without the element with the symbol N, there would be no metabolism, no protein and no DNA – neither in plants nor in animals or humans. Nitrogen represents nearly two kilograms of the total weight of a 70-kilogram adult.
The German word for nitrogen – Stickstoff – shares etymological roots with the German word for suffocation or asphyxiation and derives from nitrogen’s ability to extinguish flames as well as life. The scientific name “nitrogenium” derives from the Greek word for saltpeter (“nitros”) from which it was produced before the invention of air separation.
99 per cent of the Earth’s supply of nitrogen is found in the air. Most plants require fixed nitrogen compounds which are contained in the soil and consumed by them. That’s why more than eighty per cent of worldwide nitrogen production – some 40 million tonnes per year – is used to manufacture synthetic fertilisers.
Pure nitrogen is used for many purposes, including as a gas to fill aircraft tyres so the wheels do not catch fire due to the heat generated during takeoff and landing. The gas also serves as a propellant – to whip cream, for example – or as a shielding gas in food packaging.
Liquid nitrogen is used as a cooling medium in cryogenics – for food storage, for example, or for flash freezing. Other application areas for liquid nitrogen include concrete cooling and ground freezing in construction along with cryosurgical applications. The best-known example of the latter is the freezing of warts
In the manufacture of electronic components, e.g. for MP3 players, nitrogen is used as a shielding gas.