Doctors use iodine-131 to treat some forms of cancer. The half-life of iodine-131 is 8 days. A patient receives a treatment of 12 millicuries. A millicurie is a unit of radioactivity. How much iodine-131 remains in the patient 16 days later?
I know the answer is 3, but I want to use a function, since it is the main focus of the lesson. I having trouble setting up a function.
if the half life is 8 days, 1/2 is gone every 8 days. so after 8 days it is 1/2, 16 days is 1/4...
so at 16 days it is 12 x 1/4 = 3 mc
Another way to solve it is:
amount = 12 (1/2)^(168)
= 12(1/2)^2 = 3 millicuries
How did you get 168?
And how did you get 2?
That was a typo. She meant 16/8
since that is how many half-lives there were.