Atomic particles are the smallest components of an atom, and they can be divided into two categories: subatomic particles and elementary particles. Ions, protons, neutrons, muons, leptons, and electrons are all examples of subatomic particles. Ions are atoms that have gained or lost one or more electrons, protons are positively charged particles found in the nucleus of an atom, neutrons are uncharged particles found in the nucleus of an atom, muons are unstable subatomic particles with a negative charge, leptons are particles with no charge, and electrons are negatively charged particles found in the orbit of an atom.