

InterviewSolution
Saved Bookmarks
1. |
Half-life of a radioactive substance is T. At time t_1 activity of a radioactive substance is `R_1` and at time `t_2` it is `R_2`. Find the number of nuclei decayed in this interval of time. |
Answer» Correct Answer - A::B Half-life is given by `t_(1//2) = (1n2)/(lambda)` :. `lambda = (1n2)/(t_(1//2))=1n2/T` Activity `R= lambdaN` :. `N=R/lambda=(RT)/(1n2)` When activity is `R_1`, numbers of nuclei are `N_1 =(R_1T)/(1n2)` Similarly, `N_2 = (R_2T)/(1n2)` :. Numbers decayed `=N_1-N_2 = ((R_1-R_2)T)/(1n2)` |
|