What is an isotope like carbon-14?

An isotope like carbon-14 is a variant of the carbon element that has the same number of protons (6) but a different number of neutrons (8), resulting in a total Atomic Mass of 14. Carbon-14 is radioactive and decays over time, which makes it useful for dating organic materials in Archaeology and geology. Its stable isotopes, such as carbon-12 and carbon-13, are more common, but carbon-14's unique properties allow scientists to trace the age of ancient artifacts and fossils.