# Simple carbon dating explanation

*10-Oct-2015 14:29*

When finding the age of an organic organism we need to consider the half-life of carbon 14 as well as the rate of decay, which is –0.693.

For example, say a fossil is found that has 35% carbon 14 compared to the living sample. We can use a formula for carbon 14 dating to find the answer.

When an organism dies it ceases to replenish carbon in its tissues and the decay of carbon 14 to carbon 12 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.

Where t is the age of the fossil (or the date of death) and ln() is the natural logarithm function.

After 5,730 years, the amount of carbon 14 left in the body is half of the original amount.If the amount of carbon 14 is halved every 5,730 years, it will not take very long to reach an amount that is too small to analyze.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 carbon 12 and other particles.

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.