Radiometric dating activities
The equation relating rate constant to half-life for first order kinetics is \[ k = \dfrac \label\] so the rate constant is then \[ k = \dfrac = 1.21 \times 10^ \text^ \label\] and Equation \(\ref\) can be rewritten as \[N_t= N_o e^ \label\] or \[t = \left(\dfrac \right) t_ = 8267 \ln \dfrac = 19035 \log_ \dfrac \;\;\; (\text) \label\] The sample is assumed to have originally had the same (rate of decay) of d/min.g (where d = disintegration).
In contrast, living material exhibit an activity of 14 d/min.g.
Libby estimated that the steady-state radioactivity concentration of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram.
In 1960, Libby was awarded the Nobel Prize in chemistry for this work.
Once an organism is decoupled from these cycles (i.e., death), then the carbon-14 decays until essentially gone.
The universe is full of naturally occurring radioactive elements.