The half life of a radioactive element is 30 min. One sixteenth of the original quantity of element will be left after
a. 1 hr b. 16 hr c. 4 hr d. 2 hr

Options

A. 1 hrs
B. 16 hrs
C. 4 hrs
D. 2 hrs

Answer

D

Explanation

`(N_(0))/(2^(n))=(1)/(16)`
`N=(N_(0))/(2^(n))implies(N)/(N_(0))=(1)/(2^(n))`
`(1)/(2^(n))=(1)/(16)impliesn=4`
`therefore t=nxxt_(1//2)=4xx30` min
=120 min 2 hrs