Answer:
Okay! Had to do some research, but now I'm here.
Explanation:
So, to do this, half-life is a sort of time period where half of the starting material naturally decays into a stable element, such as uranium.
Meaning, after 17.5 days, 50 grams of that radioisotope will be left.
After 35 days (2 half-lives), 25 grams of that radioisotope will be left.
See where I'm getting at?
After 52.5 days, 12.5 grams of the radioisotope will be left.
(It's easier to create a graph, but I'm using a simple progression method to solve this.)
As such, after 70 days, <em>6.25</em> grams of that radioisotope will be left.
See? Pretty easy. Just keep adding the amount of the half-life, and divide the starting material by two!
Hope this helps!
