The half - life of` `I ^ (131)` is 8 days. Given a sample of `I^(131)` at time `t = 0` , we can assert that

Options

A. No nucleus will decay before `t = 4` days
B. No nucleus will decay before `t = 8` days
C. All nuclei will decay before `t = 16` days
D. A given nucleus may decay at any time after `t = 0`

Answer

D

Explanation

(d) Number of nuclei decreases exponentially
`N = N_0 e^(-lamda t)` and Rate of decay `(-(dN)/(dt)) = lamda N`
Therefore, decay process lost up to `t = oo`
Therefore, a given nucleus may decay at any time after `t = 0`.