Radio carbon dating calculations
The dating process is always designed to try to extract the carbon from a sample which is most representative of the original organism.
In general it is always better to date a properly identified single entity (such as a cereal grain or an identified bone) rather than a mixture of unidentified organic remains.
Since carbon is fundamental to life, occurring along with hydrogen in all organic compounds, the detection of such an isotope might form the basis for a method to establish the age of ancient materials.
Libby, a Professor of Chemistry at the University of Chicago, predicted that a radioactive isotope of carbon, known as carbon-14, would be found to occur in nature.
For radiocarbon dating to be possible, the material must once have been part of a living organism.
This means that things like stone, metal and pottery cannot usually be directly dated by this means unless there is some organic material embedded or left as a residue.
The ensuing atomic interactions create a steady supply of c14 that rapidly diffuses throughout the atmosphere.
In contrast, methane made from petroleum products had no measurable radioactivity.
There are also trace amounts of the unstable radioisotope carbon-14 (14C) on Earth.