Subatomic Particle having a single positive electrical charge and constituting the nucleus of
the ordinary Hydrogen Atom. Every atomic nucleus contains one or more protons. The Mass of the proton is about 1,840 times the mass of the Electron and slightly less than the mass of the Neutron. Protons are made of still smaller particles called Quarks. In 1919 Rutherford, Ernest discovered the proton as a product of the disintegration of the atomic
nucleus. The antiproton, the proton's Antiparticle (see Antimatter), was discovered in 1955. Research into the possibility that the proton may
decay has been inconclusive but suggests that its lifeTime is at least 1031 years. See Elementary Particles.