Neutron

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.