Molecule

A molecule is a group of two or more atoms held together by chemical bonds. It is the smallest unit of a chemical compound that keeps the substance's properties.

Examples

A water molecule is made of two hydrogen atoms and one oxygen atom (H2O). Oxygen gas is two oxygen atoms bonded together.

Importance

Everything around us — air, water, food and living tissue — is made of molecules. The study of how they form and react is central to chemistry.

Frequently asked questions

What is a molecule?

Two or more atoms bonded together.

What is a water molecule made of?

Two hydrogen atoms and one oxygen atom.