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.