If a radioactive isotope were injected into your bloodstream, how many half- lives would you have to wait before the amount of this isotope in your body is 1 its original amount? 16
A)1
B)2
C)3
D)4
E)5

Question

Quizplus · Accepted Answer

To determine the number of half-lives required for the amount of the isotope to decrease to 1/16th of its original amount, we need to continuously divide the amount by 2 until we reach 1/16. This requires 4 divisions, or 4 half-lives. Therefore, the answer is D) 4.

If a Radioactive Isotope Were Injected into Your Bloodstream, How