The half life of `I""^(131)` is 8 day. Given a sample of `I""^(131)` at t=0, we can assert that a)No nucleus will decay at t=4day b)No nucleus will de

Monjur Alahi

The half life of `I""^(131)` is 8 day. Given a sample of `I""^(131)` at t=0, we can assert that a)No nucleus will decay at t=4day b)No nucleus will decay before t=8day c)All nucleus will decay before t=16day d)A given nucleus may decay before
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`


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Salim Ahmed Kawsar

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Correct Answer - D
Number of nuclei decreases experientially
`N=N_(0)e^(-lambdat)` and Rate of decay `(-(dN)/(dt))=lambdaN`
Therefore, decay process lasts upto `t=oo`. Therefore a given nucleus may decay at any time after `t=0`.

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