A piece of radioactive material contains 1000 atmos. If its half -life is 20seconds, the time taken for 125 atoms to remain is
-
A.
20 seconds -
B.
40 seconds -
C.
80 seconds -
D.
60 seconds
Correct Answer: Option D
Explanation
1000 → 500 → 250 → 125
20 + 20 + 20 = 60s