If you have 200 grams of a radioactive sample, how many grams would be left after three half-lives?
select one:
a. 200
b. 150
c. 50
d. 25

Well, after 1 half life, depending on whatever the amount is, 50% of the original content and or remaining content will undergo decay, as it is unstable.

Original content - 200g

1 half life - 100 g
2 half life - 50 g
3 half life - 25 g

The correct solution would be D. 25 g.