Q. The half-life of radioactive Radon is 3.8 days. The time at the end of which (1/20)th of the Radon sample will remain undecayed is (given ${\log_{10}e}{= 0.4343)}$
A) 13.8 days
B) 16.5 days
C) 33 days
D) 76 days
Explanation
(b) $\left( \frac{1}{2} \right)^{n} = \frac{N}{N_{0}} = \frac{1}{20}given\ n = 4.32$
$t = n \times T = 4.32 \times 3.8$
$= 16.4\ days$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.