Question

If we start with 16 grams of a radioactive substance, how much will remain after three half-lives

Answer 1

Hey there!

A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.

So, we divide the 16g sample in half 3 times.

16 ÷ 2 = 8

8 ÷ 2 = 4

4 ÷ 2 = 2

There will be 2g of the radioactive sample remaining after three half lives.

Hope this helps!