Nitrogen [ Return towards Air gases ]

Nitrogen (N₂) is a molecule composed of two atoms. It’s the main constituent of the atmosphere since it represents 78% of the air we breathe in terms of volume. It is essential as it dilutes oxygen which would reach such high concentration without it that it would be harmful for human beings.

It was discovered in 1772 by Daniel Rutherford.

More about nitrogen history

To produce nitrogen, it is necessary to separate it from the other components of air, notably from oxygen (21%). Air can be liquefied at an extremely low temperature (of around -190°C). Its components (nitrogen, oxygen, noble gases) are then separated through distillation.

Another method consists in forcing air through polymer membranes in the shape of hair-thin hollow tubes. Oxygen passes through these membranes faster than nitrogen. The air coming into these tubes gradually becomes poorer in oxygen and richer in nitrogen.

More about nitrogen production

At normal temperature and pressure, nitrogen is a colorless, odorless, and tasteless gas. It is inert, which means that it doesn’t react with any other substances under normal temperature and pressure conditions.

It is used as a protective atmosphere in large numbers of industrial processes. For example, it protects against oxidation of foodstuffs in the food industry and against impurities during microprocessors manufacturing.

In the liquid state (-196°C under normal atmospheric pressure conditions), nitrogen is a powerful coolant, making it useful in cryogenics.

Discover the various applications of nitrogen

More about this gas: its physico-chemical properties