Carbon-14

Carbon-14 is a radioactive isotope of carbon found in the atmosphere, produced by cosmic rays interacting with nitrogen. Living organisms absorb Carbon-14 through carbon dioxide. When they die, they stop taking in Carbon-14, and the isotope slowly decays at a known rate, called its half-life (about 5,730 years). By measuring the remaining Carbon-14 in a sample, scientists can estimate how long it has been since the organism died. This method, known as radiocarbon dating, is widely used in archaeology and geology to date ancient artifacts and fossils, providing insights into past life and environmental changes.