(b) A radioactive sample with an initial radioactivity of 10.0 mCi was obtained for analysis. The half-life of the radioactive sample is expected to be 24 hours. (i) Calculate the theoretical sample's activity after 7.20 hours. (3 marks) (ii) Determine the number of radioisotope nuclide that is corresponding to the answer as obtained in Q2 (b) (i). (4 marks) (iii) During the radioactivity measurement of the samples, the actual final radioactivity is much lesser than the value as obtained in Q2 {h} {i}. Evaluate whether the half-life of the samples is longer or shorter than 24 hours. (2 marks) (iv) Another identical radioactive sample was also analysed in the same lab. However, the radioactivity of this sample after 7.20 hours was found to be higher than the theoretical value found in Q2 (h) (i). Explain and justify what is the possible cause for the reading to be higher. (2 marks)