Radiometric dating and the geological time scale
A particular isotope of a particular element is called a nuclide. That is, at some point in time, an atom of such a nuclide will spontaneously change into a different nuclide by radioactive decay.The decay may happen by emission of particles (usually electrons (beta decay), positrons or alpha particles) or by spontaneous nuclear fission, and electron capture.Radiometric dating is also used to date archaeological materials, including ancient artifacts.
Known for the diversification and evolution of life, along with the formation of Pangea.
Using this time scale, geologists can place all events of Earth history in order without ever knowing their numerical ages.