Radioactivity of `108` undecayed radioactive nuclei of half life of `50` days is equal to that of `1.2 xx 108` number of undecayed nuclei of some material with half life of `60` days
Radioactivity is proportional to half-life.

Options

A. If both, Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
B. If both, Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is true but the Reason is false.
D. If both Assertion and Reason are false.

Answer

C

Explanation

Radioactivity `=-(dN)/(dt)=lambdaN=(0.693N)/T`
`=(0.693xx10^(8))/50=(0.693xx1.2xx10^(8))/60`
`implies 0.693xx2xx10^(6)`
So, assertion is true but radioactivity `prop1/T` and not T. Therefore, the reason is false.