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

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

* Electrons: Negatively charged particles that orbit the nucleus in shells or energy levels.

While these are the fundamental building blocks of all atoms, there are other subatomic particles that exist, but are not found in all atoms. These include:

* Quarks: Fundamental particles that make up protons and neutrons.

* Leptons: Fundamental particles that include electrons and neutrinos.

* Bosons: Force carrier particles that mediate interactions between other particles.

Let me know if you'd like to learn more about any of these particles!