Radioactive isotopes in carbon dating
In the case of radiocarbon dating, the half-life of carbon 14 is 5,730 years.
This half life is a relatively small number, which means that carbon 14 dating is not particularly helpful for very recent deaths and deaths more than 50,000 years ago.
Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon.
The half-life of a radioactive isotope describes the amount of time that it takes half of the isotope in a sample to decay.
Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material.