Dating prehistoric objects
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.
Radiation counters are used to detect the electrons given off by decaying Carbon-14 as it turns into nitrogen.
The rate of decay of N in 5,730 years (plus or minus 40 years).
This is the “half-life.” So, in two half-lives, or 11,460 years, only one-quarter of that in living organisms at present, then it has a theoretical age of 11,460 years.
Anything over about 50,000 years old, should theoretically have no detectable C.
That is, they take up less than would be expected and so they test older than they really are.