Proton

Later experiments suggested that the positive charge of any nucleus could be divided into a whole number of smaller, identical units of positive charge. These particles were named protons. This refined the meaning of a positively charged nucleus: its charge comes from the protons it contains.

An atom is made of three kinds of smaller, or subatomic, particle: protons, neutrons and electrons. They are not spread evenly throughout it. At the centre is the nucleus, which contains the protons and neutrons.

The nucleus contains protons and neutrons. Protons are positively charged, neutrons have no charge, and electrons are negatively charged.

Atoms contain three important subatomic particles: protons, neutrons and electrons. Protons and neutrons are in the nucleus, while electrons occupy shells around it. To compare these particles conveniently, chemists use relative charge and relative mass.