Q. For a radioactive material, half-life is 10 minutes. If initially there are 600 number of nuclei, the time taken (in minutes) for the disintegration of 450 nuclei is
A) 30
B) 10
C) 20
D) 15
Explanation
[Solution] 150 nuclei remain = 600/4, i.e. two half-lives = 20 minutes. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.