The smallest unit of matter is the atom. It is also the smallest unit of matter that has chemical properties.
A subatomic particle is one that is smaller than an atom in size. Protons, electrons, and neutrons are the subatomic particles that make an atom. As a result, an atom can be broken into these subatomic particles.
The nucleus of an atom is made up of nucleons i.e. neutrons and protons together. Neutrons are neutral particles, whereas protons are positively charged.
Electrons are negatively charged particles that revolve around the nucleus of an atom.
Therefore, the atom is divisible into its subatomic particles.