Question 48
Radioactivity and Nuclear PhysicsA substance has a half life of 3 min. After 6 min, the count rate was observed to be 400. What was its count rate at zero time?
- A.200
- B.1200
- C.1600
- D.2400
Show the answer and explanation
Answer: C (1600)
Explanation
6 min is two half-lives, so the count rate has fallen to a quarter: original = 400 × 4 = 1600.