There are three principal isotopes of carbon which occur naturally - C12, C13 (both stable) and C14 (unstable or radioactive).
These isotopes are present in the following amounts C12 - 98.89%, C13 - 1.11% and C14 - 0.00000000010%.
Radiocarbon dating is a method of estimating the age of organic material.
Radiocarbon dating has been one of the most significant discoveries in 20th century science.
Renfrew (1973) called it 'the radiocarbon revolution' in describing its impact upon the human sciences.
In order to date the artifact, the amount of Carbon-14 is compared to the amount of Carbon-12 (the stable form of carbon) to determine how much radiocarbon has decayed.
The ratio of carbon-12 to carbon-14 is the same in all living things.
Libby of the University of Chicago in immediate post-WW2 years.
Libby later received the Nobel Prize in Chemistry in 1960: (From Taylor, 1987).When these energetic neutrons collide with a nitrogen-14 (seven protons, seven neutrons) atom it turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).Since Nitrogen gas makes up about 78 percent of the Earth's air, by volume, a considerable amount of Carbon-14 is produced.By measuring the ratio of carbon-12 to carbon-14 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of the artifact."Everything which has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time we cannot measure.Libby and coworkers, and it has provided a way to determine the ages of different materials in archeology, geology, geophysics, and other branches of science.