Question

Iodine-123, which is used for diagnostic imaging in the thyroid, has a half-life of 13 hours. If 50.0 mg of I-123 were prepared at 8:00 A.M. on Monday, how many mg remain at 10:00 A.M. on the following day

Answer 1

Answer: 12.5 mg

Explanation:

The half-life of Iodine -123 is 13 hours.

Between 8 am on Monday and 10 am on Tuesday will be 26 hours.

After the first 13 hours, the Iodine should be left with half of its initial quantity

= 50/2

= 25 mg

There are now 13 hours remaining meaning that the Iodine will be half of the 25mg after that period.

= 25/2

= 12.5 mg.

12.5 mg remain at 10 am the next day.

Please do react or comment if you need any clarification or if the answer helped you. This would help other users as well. Thank you.