What is nitrogen?

  • Nitrogen is an element. It's a gas at room temperature.

  • Nitrogen makes up about 78% of the Earth's atmosphere.

  • Liquid nitrogen is very cold, so it is often used to freeze food.

A short video explaining where nitrogen can be found and used.

How is nitrogen used?

Nitrogen has just one type of atom, so it is an element. It's found naturally as a molecule, each containing two nitrogen atoms. This gives it a chemical formula of N₂. Nitrogen has a low melting and boiling point and is a gas at room temperature.

The Earth’s atmosphere is made up of 78% nitrogen. The next most common gas is oxygen, at 21%. Nitrogen isn't very reactive, but it can react with oxygen at high temperatures, such as in car engines. These reactions make nitrogen oxides.

The boiling point of nitrogen is −196 °C, so liquid nitrogen is very cold indeed. This means liquid nitrogen is ideal for freezing food, such as vegetables, very quickly, allowing them to stay fresher for longer.

A rotating model of a nitrogen molecule.