The first atomic explosion was detonated in the desert north of Alamogordo, New Mexico, on July 16, 1945. What fraction of the strontium-90 ( years) originally produced by that explosion still remains as of July 16, 2006? In Addition, Iodine-131 is used in the diagnosis and treatment of thyroid disease and has a half-life of 8.1 days. If a patient with thyroid disease consumes a sample of Na131I containing 10 of 131I, how long will it take for the amount of 131I to decrease to of the original amount?