(a)[2]
State the meaning of radioactive decay.
(b)
Fig. 13.1 shows how the number $N$ of technetium-101 nuclei in a radioactive sample changes with time $t$.
(b(i))[4]
Use Fig. 13.1 to find the activity, in $\text{Bq}$, of the technetium-101 sample at time $t = 14.0$ minutes. Show your working.
(b(ii))[2]
Without first finding the half-life of technetium-101, use your answer in (i) to work out the decay constant $\lambda$ of technetium-101.