The three main subatomic particles are:

* Protons: Positively charged particles found in the nucleus of an atom.

* Neutrons: Neutrally charged particles also found in the nucleus.

* Electrons: Negatively charged particles that orbit the nucleus in a cloud-like region called the electron cloud.

There are also other subatomic particles like quarks and leptons, but protons, neutrons, and electrons are the fundamental building blocks of atoms.