The half-life period of a radioactive element is 140 days. After 560 days, one gram of the element will reduce

Options

A. 1/2 g
B. 1/4 g
C. 1/8 g
D. 1/16 g

Answer

D

Explanation

`T = n xx t_(1//2) therefore n = (T)/(t_(1//2)) = (560)/(140) = 4 "Now", N_(t) = N_(0) ((1)/(2))^(n) = 1((1)/(2))^(4) = (1)/(16)g`