Atom Parts is a term used to describe the components of an atom. The four main parts are protons, neutrons, electrons, and nuclei. Protons are positively charged particles located in the nucleus of an atom, while neutrons are neutral particles also found in the nucleus. Electrons are negatively charged particles that orbit around the nucleus, and the nucleus is the center of the atom, containing both protons and neutrons. TONS is an acronym for these four parts, standing for 'protons, neutrons, electrons, and nuclei'.