The difference between a stable isotope and an unstable isotope
A "stable isotope" is any of two or more forms of an element whos nuclei contains the same number of protons and electrons, but a different number of neutrons. Stable isotopes remain unchanged indefinitely, but "unstable" (radioactive) isotopes undergo spontaneous disintegration.
Genetic drift is a change in the frequency of an allele within a population over time. There are no environmental influences that cause genetic drift to occur.
