Scientific definition radioactive dating
This radioactivity can be used for dating, since a radioactive 'parent' element decays into a stable 'daughter' element at a constant rate.The rate of decay (given the symbol λ) is the fraction of the 'parent' atoms that decay in unit time.All rely on the fact that certain elements (particularly uranium and potassium) contain a number of different isotopes whose half-life is exactly known and therefore the relative concentrations of these isotopes within a rock or mineral can measure the age.
Another way of expressing this is the half-life period (given the symbol T).
Therefore, the half-life of a radioactive element is independent of the amount of sample.
With the help of half-life values of a suitable radioisotope of an element, which is present in a rock, or in an artifact, the age of the rock and the artifact can be determined.
This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks. Some do not change with time and form stable isotopes (i.e.
those that form during chemical reactions without breaking down).