Can you imagine someone who lived over 2400 years ago saying that all matter is made up of atoms?

Two presenters use animations to show how protons, neutrons and electrons make up atoms. They explain the relative masses, sizes, locations and charges of these subatomic particles. Introduce ...

Molecules are made when two or more atoms chemically bond together. Atoms from different elements can combine. When the atoms are from different elements, the molecule can also be called a compound.