the same number of protons but different number of neutrons, the same number of neutrons but different number of protons, equal number of protons and electrons, equal number of nucleons" /> the same number of protons but different number of neutrons, the same number of neutrons but different number of protons, equal number of protons and electrons, equal number of nucleons" /> the same number of protons but different number of neutrons, the same number of neutrons but different number of protons, equal number of protons and electrons, equal number of nucleons" />