Which of the following isotopes of carbon is used in radiocarbon dating?

Carbon-14 is the isotope used in radiocarbon dating due to its unique properties and stability. It is a radioactive isotope that forms in the atmosphere when cosmic rays interact with nitrogen-14. Living organisms constantly take in carbon from their environment, including carbon-14, through processes like photosynthesis and the food chain.

When an organism dies, it stops taking in carbon, and the carbon-14 it contains begins to decay at a known rate, with a half-life of approximately 5,730 years. By measuring the remaining concentration of carbon-14 in a sample and comparing it to the amount of carbon-14 that would have been present while the organism was alive, scientists can estimate the time of its death, thus dating archaeological and geological samples.

In contrast, the other isotopes of carbon—carbon-12, carbon-13, and carbon-15—are stable and do not undergo radioactive decay. Therefore, they cannot provide the same dating capability as carbon-14, making it the isotope of choice for radiocarbon dating methods.