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One gram of radium is reduced by `2` miligram in `5` yers by `alpha`-decay. Calculate the half-life of radium.A. 1700 yrB. 1000 yrC. 1115 yrD. 979 yr |
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Answer» Correct Answer - 1 `N_(0) = gm` `N=1 g-2 mg=0.998 g` `t=5 yr` `use,N = N_(0)e^(-lambdat)` `(N_(0))/(N)=e^(5 lambda)` `(1)/(0.9989) = e^(5lambda)` "taking log both sides" `5lamda =ln(1.0020)` and T=(0.693)/(lambda)=1672 yr` |
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