Nitrogen is a colourless gas that you can’t smell. It makes up about 78 % of the Earth’s atmosphere.

Nitrogen’s chemical symbol is N. Its atomic number is 7 and its mass is 14. Nitrogen gas has two atoms bonded together to form a molecule. The gas can be made into a liquid that freezes at -209° and boils at 195 ° C.

All plants and animals must have nitrogen to live. It is part of all amino acids. Plants produce these acids themselves, animals only produce some of them and get the rest by eating other animals and plants,

Nitrogen is also used as a fertilizer, which plants need to grow.