* Protons: These are positively charged particles located in the nucleus of an atom.

* Neutrons: These are neutral particles (no charge) also located in the nucleus.

* Electrons: These are negatively charged particles that orbit the nucleus in shells or energy levels.

These subatomic particles are much smaller than the atom itself. While protons and neutrons have similar masses, electrons are significantly lighter. The arrangement and number of these particles determine the element and its properties.