After 2 hours, a radioactive substance becomes `((1)/(16))^(th)` of original amount. Then the half life (in min) is

Options

A. 60 minutes
B. 120 minutes
C. 30 minutes
D. 15 minutes

Explanation

`t overset(1//2) to (1/2) overset(t_(1//2)) to (1/4) overset(t_(1//2)) to (1/8) overset(t_(1//2)) to (1/16)`
`therefore 4 t^(1//2) = 2` hours `rArr t^(1//2) = 30` min.