Q. Half-life of a radio active substance A is 4 days. The probability that a nucleus will decay in two half-lives is
A) $\frac{1}{4}$
B) $\frac{3}{4}$
C) $\frac{1}{2}$
D) 1
Explanation
(b) After two half-lives $\frac{1}{4}$ th fraction of nuclei will remain undecayed or $\frac{3}{4}th$ fraction will decay. Hence , the probability that a nucleus decays in two half-lives is $\frac{3}{4}.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.