Radiology General b7120e04 Which of the following represents the half life of I123 ? A 3. 2 hours B 13.2 hours C 8 days D 10 days High-Yield Explanation Half life of radioisotope I 123 is 13.2 hours. Half life of I 124 is 4.2 days and that of I 131 is 8days.