Carbon radioactive isotope dating

The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate.Organisms capture a certain amount of carbon-14 from the atmosphere when they are alive.

carbon radioactive isotope dating-13

Where t is the age of the fossil (or the date of death) and ln() is the natural logarithm function.If the fossil has 35% of its carbon 14 still, then we can substitute values into our equation.Carbon is naturally in all living organisms and is replenished in the tissues by eating other organisms or by breathing air that contains carbon.At any particular time all living organisms have approximately the same ratio of carbon 12 to carbon 14 in their tissues.The carbon-14 it contained at the time of death decays over a long period of time, and the radioactivity of the material decreases.

The approximate time since the organism died can be worked out by measuring the amount of carbon-14 left in its remains compared to the amount in living organisms.When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to nitrogen 14 changes the ratio of carbon 12 to carbon 14.Experts can compare the ratio of carbon 12 to carbon 14 in dead material to the ratio when the organism was alive to estimate the date of its death.Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material.The stable form of carbon is carbon 12 and the radioactive isotope carbon 14 decays over time into nitrogen 14 and other particles.By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.