Science glossary film: Molecule

Two or more atoms held strongly together by covalent bonds. Molecules can contain atoms of a single element, such as oxygen molecules which consist of a pair of oxygen atoms. Or they can contain atoms of different elements: from water molecules, H₂O, to huge, complex organic compounds, such as DNA.

Molecules can contain atoms of a single element, such as oxygen molecules which consist of a pair of oxygen atoms. Or they can contain atoms of different elements: from water molecules, H₂O, to huge, complex organic compounds, such as DNA.