In the medical treatment of abnormal thyroid glands, doctors administer a solution of radioactive sodium jodide. It has an activity of 5 x 10 Bq. The atoms of iodine are radioactive; they have a half-life of about 13 hours. a Suggest why a radioactive isotope with a half-life of about 13 hours is appropriate for a medical procedure. b Calculate how many atoms of iodine are required to produce an activity of 5x 10 Bq.