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Define activity of a sample of a radioactive substance. The value of the disintegration constant of a radioactive substance is 0.0693h^(-1). Find the time after which the activity of a sample of this substance reduces to one-half that of its present value. |
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Answer» Solution :ACTIVITY of a sample of a radioactive substance is defined as the RATE of of distingeration of that substance PER unit time. Activity `R_((f))=-(d N_((t)))/(t)=lambda N_((t))`. where `lambda`= disintegration and `N_((t))` the number of radioactive nuclei at that time. We know that activity of a sample is reduced to one half of its initial time `t=T_(1/2)=(0.0693)/(lambda)` As per question `lambda=0.0693 h^(-1)` `rArr t=(0.0693)/(0.0693) =10H` |
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