Answer :
Answer: C. half life
Explanation:-
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is represented by [tex]t_{\frac{1}{2}[/tex]
[tex]t_{\frac{1}{2}=\frac{0.693}{\lambda}[/tex]
[tex]\lambda[/tex] = rate constant