Proton

In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1.602 × 10−19 coulomb), a diameter of about 1.5×10−15 m, and a mass of 938.27231(28) MeV/c2 (1.6726 × 10⁻²⁷ kg), 1.007 276 466 88(13) u or about 1836 times the mass of an electron.