Purpose of radioactive dating
Organic materials typically contain small amounts of radioactive carbon and potassium.
Cosmic radiation from the Sun and other stars is a source of background radiation on Earth.
A radioactive isotope, also known as a radioisotope, radionuclide, or radioactive nuclide, is any of several species of the same chemical element with different masses whose nuclei are unstable and dissipate excess energy by spontaneously emitting radiation in the form of alpha, beta, and gamma rays.
Every chemical element has one or more radioactive isotopes.
Each “parent” radioactive isotope eventually decays into one or at most a few stable isotope “daughters” specific to that parent. Some radioactive isotopes are present as terrestrial radiation.