Age of fossil may be found out by determining the ratio of two isotopes of carbon. The isotopes are—

Radiocarbon dating is a scientific method used to determine the age of organic materials by measuring the ratio of carbon isotopes. There are three naturally occurring isotopes of carbon: Carbon-12 (12C), Carbon-13 (13C), and Carbon-14 (14C). While 12C and 13C are stable, 14C is radioactive and decays over time with a half-life of approximately 5,730 years. Living organisms maintain a nearly constant ratio of 14C to 12C by exchanging carbon with the atmosphere. Upon death, this exchange stops, and the 14C begins to decay while the amount of stable 12C remains constant. By determining the remaining ratio of Carbon-14 to Carbon-12, scientists can calculate the time elapsed since the organism's death. This technique is effective for dating organic remains up to approximately 60,000 years old.