A typical atom consists of three subatomic particles: protons, neutrons, and electrons. Other particles exist as well, such as alpha and beta particles. Most of an atom's mass is in the nucleus—a smal...A typical atom consists of three subatomic particles: protons, neutrons, and electrons. Other particles exist as well, such as alpha and beta particles. Most of an atom's mass is in the nucleus—a small, dense area at the center of every atom, composed of nucleons including protons and neutrons. All the positive charge of an atom is contained in the nucleus, and originates from the protons. Neutrons are neutrally-charged. Electrons, which are negatively-charged, are located outside of the nucleus
