Question

Select One Option correct from the following: Half-life of a radioactive 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.

Answer 1

Answer : (d) $\;\large\frac{3}{4}$

Explanation :

After two half lives $\;\large\frac{1}{4}^{th}\;$ fraction of nuclei will remain undecayed . or $\;\large\frac{3}{4}^{th}\;$ fraction will decay hence the probability that a nucleus decays in two half lives is $\large\frac{3}{4}$