Final answer:
After 2 months, approximately 39.06 grams of iodine-131 will remain from the original 625-gram sample.
Step-by-step explanation:
The half-life of iodine-131 is 15 days. To determine how much iodine-131 will remain after 2 months (which is equivalent to 60 days), we can calculate the number of half-lives that have passed in that time period. 2 months is equal to 4 half-lives (60 days divided by 15 days). Each half-life reduces the amount of the radioactive substance by half. So, after 4 half-lives, the remaining amount will be 1/16th of the original amount.
Given that the original sample size is 625 grams, the amount remaining after 2 months will be:
625 grams x (1/2)4 = 625 grams x 1/16 = 39.06 grams (rounded to two decimal places).