We’re back to memorising definitions - it is sad but true. These three words are used so often in chemistry that not knowing them is like shooting yourself in the foot with an atomic bomb. This is one of the times where you have to learn the definitions word for word so we have kept them short and to the point and included diagrams to illustrate the point visually:

Element

A substance that contains only one type of atom.

 Compound

Two or more substances that are chemically joined together.

Mixture

Two or more substances together but not chemically joined.