A proton is a positively charged particle that is approximately 1.67*10^-27 kilograms in size. Protons can also be measured in Mega-Electron Volts. In Mega-Electron Volts, a proton is approximately equal to 938.27.
A proton is roughly the same size as a neutron, but it is much larger than its negative counterpart, the electron. In an atom, protons and neutrons stick together to make up the nucleus at the center of the atom. Electrons float around the nucleus in orbits. In total, atoms are comprised of electrons, protons and neutrons. Each atom has a different number of each of these microscopic particles.