The half-life of iodine-131 is 8 days. If a patient is administered a 1,700-microgram dose of iodine-131 , how much iodine-131 will be in the patient's system after 8 days and after 22 days?
A) 850 micrograms after 8 days; 265.1 micrograms after 22 days
B) 850 micrograms after 8 days; 239.6 micrograms after 22 days
C) 850 micrograms after 8 days; 252.7 micrograms after 22 days
D) 850 micrograms after 8 days; 425 micrograms after 22 days
E) 850 micrograms after 8 days; 258.5 micrograms after 22 days

Question

Quizplus · Accepted Answer

After 8 days (one half-life), the amount is halved to 850 micrograms. After 22 days, which is 2.75 half-lives, the amount is reduced to approximately 252.7 micrograms.

The Half-Life of Iodine-131 Is 8 Days