Carbon -14 dating method is based on the fact that:
The living matter contains a definite amount of the radioactive carbon isotope C14
The amount of carbon−14 is compared to the amount of carbon−12 to determine how much radiocarbon has decayed.
The ratio of carbon−12 to carbon−14 is the same in all the living things.
At the moment of death, the amount of C−12 remains constant in the sample but the amount of C−14 decreases because it is unstable.
By measuring the ratio of carbon−12 tocarbon−14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of the artifact.