Carbon-14 dating, also called radiocarbon dating, method of age determination that depends upon the decay to nitrogen of radiocarbon (carbon-14). Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.

Why is carbon-14 most useful in telling the age of fossils?

Every 5,730 years, the radioactivity of carbon-14 decays by half. That half-life is critical to radiocarbon dating. Since carbon-12 doesnt decay, its a good benchmark against which to measure carbon-14s inevitable demise. The less radioactivity a carbon-14 isotope emits, the older it is.

Why is carbon-14 useful to determine the age of organic remains?

While the most common form of carbon has six neutrons, carbon-14 has two extra. That makes the isotope heavier and much less stable than the most common carbon form. The half-life of carbon-14 is 5,730 years, making it ideal for scientists who want to study the last 50,000 years of history.