isotope chart

An isotope is a variation of a chemical element with the same number of protons but a different number of neutrons. This difference in neutrons results in different atomic masses and physical properties, though chemical behavior remains largely the same. For example, hydrogen has three isotopes: protium (0 neutrons), deuterium (1 neutron), and tritium (2 neutrons).1

Nuclides are specific atomic species defined by their proton and neutron counts, as well as their nuclear energy state. An isotope chart, or "valley of stability," maps these nuclides based on their proton and neutron numbers, illustrating which combinations are most stable. Stable isotopes do not spontaneously change, while unstable isotopes undergo radioactive decay. Approximately 1,700 nuclides are known, with about 300 being stable and the rest radioactive.234