Answer:
Half life
Explanation:
The radioactive dating method is usually used to date a rock or a fossil in order to determine its relative age. The unstable isotope elements decays at a certain rate, which normally remains constant and are generally expressed in terms of its half life. Half life is described as the time required by any isotope element to decay half of its original amount. This half life value varies from elements to elements. For example, the half life of Carbon-14 is approximately 5700 years. This half life of an unstable isotope element plays an important role in the radioactive dating method.
