Application isotopes carbon dating
C-12 is by far the most common isotope, while only about one in a trillion carbon atoms is C-14.
C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).
We must also assume that the ratio of C-12 to C-14 in the atmosphere has remained constant throughout the unobservable past (so we can know what the ratio was at the time of the specimen's death).
It takes another 5,730 for half of the remainder to decay, and then another 5,730 for half of what's left then to decay and so on.It also allows the estimation of the age of geological samples using the decay of long lived nuclides.All radioactive decays follow first order kinetics.We have to assume, for example, that the rate of decay (that is, a 5,730 year half-life) has remained constant throughout the unobservable past.However, there is strong evidence which suggests that radioactive decay may have been greatly accelerated in the unobservable past.