atoms are characterized by number of
View Full Document. Isotopes â¢ Nuclide â A type of atom characterized by the number of protons and neutrons in the nucleus of every atom of this type. â¢ Isotopes â Atoms with the same number of protons (same element) but containing different numbers of neutrons. â Nuclides with same atomic number but different atomic masses. This preview has intentionally blurred sections.