Radio carbon dating explained
The unstable carbon-14 gradually decays to carbon-12 at a steady rate. Scientists measure the ratio of carbon isotopes to be able to estimate how far back in time a biological sample was active or alive.
All carbon atoms have a nucleus containing six protons.
As a result it is always undergoing natural radioactive decay while the abundances of the other isotopes are unchanged.
Carbon-14 is most abundant in atmospheric carbon dioxide because it is constantly being produced by collisions between nitrogen atoms and cosmic rays at the upper limits of the atmosphere.
The pathway from the plant to the molecule may have been indirect or lengthy, involving multiple physical, chemical, and biological processes.
Levels of C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.
They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.