Question & Answer: Iodine-131, t_1/2 = 8.0 days, is used in diagnosis and treatment of thyroid gland diseases. If a…..

Iodine-131, t_1/2 = 8.0 days, is used in diagnosis and treatment of thyroid gland diseases. If a laboratory sample of iodine-131 initially emits 9.45 times 10^18 beta particles per day, how long will it take for the activity to drop to 6.29 times 10^17 beta particles per day? Time _____