How are isotopes and radioisotopes different?
Isotopes are sets of nuclides having the same number of protons, but different number of neutrons. In other words, the same atomic number but a different atomic mass. Each individual isotope is a separate nuclide. Isotopes that are unstable and undergo radioactive decay are called radioisotopes. A change in the number of neutrons does not affect the charge of the atom. Every known element has isotopic forms (although some natural elements only have artificially-created isotopes), and heavier elements tend to have more isotopes than lighter elements. Naturally-occurring element have one isotope that is most common. In some cases, the dominant isotope accounts for all, or nearly all, of that elements found in nature. In other cases, the proportion may be nearly equal among two or more isotopes. The atomic mass assigned to the element in the periodic table usually represents an average of the masses of its isotopes. The average has been adjusted (weighted) to reflect the relative abundanc
