Question 10
Radioactivity and Nuclear PhysicsA radioactive substance has a half-life of 20 days. What fraction of the original radioactive nuclei will remain after 80 days?
- A.1/16
- B.1/8
- C.1/4
- D.1/32.
Show the answer and explanation
Answer: A (1/16)
Explanation
80 days ÷ 20 days = 4 half-lives. The fraction left is (½)4 = 1/16.