Protons: <span>The mass of the proton is about 1,840 times the mass of the electron and slightly less than the mass of the neutron. Electrons: </span><span>Electrons are arranged around the nucleus of atoms in regions called electron clouds or electron orbits. Neutrons: </span><span>A neutron is one of two particles found inside the nucleus (central part) of an atom. The other particle is called a proton. Electrons are particles that move around an atom outside the nucleus.</span>
