Carbon dating is based upon the decay of 14C, a radioactive isotope of carbon with a relatively long half-life (5700 years). While 12C is the most abundant carbon isotope, there is a close to constant ratio of 12C to 14C in the environment, and hence in the molecules, cells, and tissues of living organisms.

How was the half-life of carbon-14 determined?

Explanation: The level of radioactive Carbon was measured in organisms that had just died. The samples were then measured after a period of time to find the new levels of radioactivity. The loss of radioactivity was then extrapolated backwards to find the half life.

What is the half-life of carbon 14 dating?

5,730 ± 40 years Carbon-14 has a half-life of 5,730 ± 40 years—i.e., half the amount of the radioisotope present at any given time will undergo spontaneous disintegration during the succeeding 5,730 years.

How does carbon dating relate to half-life?

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.