Question

Iodine-131 is used I'd diagnosing certain medical problems because of the short half-life, which is 8.02 days. Assume the hospital lab uses for 4.52g of iodine-131 in a month. What mass of this radioisotope remains in patients after 32 days?

Answer 1

Amount/dosage=e^(-.693*32/8.02)

put this into your google search window:
e^(-.693*32/8.02)=

multiply that by the original dose, 4.52 grams, and you have it.