Physics

Problem

A radioisotope has a half-life of

5\,\text{h}

. The initial activity of a sealed source of this nuclide is

8.0\times10^{3}\,\text{Bq}

. a. (i) Calculate the number of half-lives that elapse in

15\,\text{h}

. (Take

1\,\text{h}=3600\,\text{s}

.) b. (ii) Determine the activity of the source after this time. c. (iii) What fraction of the initial nuclei has decayed during the

15\,\text{h}

period?