Atoms, elements & compounds

ATOMS

A nucleus with electrons around it.

Proton: positive (+)

Neutron: no charge

Electron: negative (−)

ELEMENT

Only one type of atom.

O₂: two oxygen atoms joined.

COMPOUND

Different elements chemically joined.

H₂O: two hydrogen atoms and one oxygen atom.

MIXTURE

Different substances together, not chemically joined to each other.