If half-life of a radioactive element is `3` hours. After `9` hours its activity becomes

Options

A. `1//9`
B. `1//27`
C. `1//6`
D. `1//8`

Answer

D

Explanation

(d) By using `A = A_0 ((1)/(2))^((t)/(T_1//2)) rArr (A)/(A_0)= ((1)/(2))^(9//3)= (1)/(8)`.