Question
State the law of radioactive decay.
Plot a graph showing the number (N) of undecayed nuclei as a function of time (t) for a given radioactive sample having half-life T½.
Depict in the plot the number of undecayed nuclei at (i) t = 3 T½ and (ii) t = 5 T½.Solution
Law of radioactive decay states that, the number of nuclei undergoing decay per unit time, at any instant, is proportional to the total number of nuclei present in the sample at that instant.
Number of undecayed nuclei at t = 3T1/2 is 
And, at t = 5T1/2 the number of undecayed nuclei is 
