InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
The half-life of a radioactive substance is 100 years. Calculate in how many years the activity will decay to `1//10^(th)` of its initial value. |
|
Answer» T = 100 years `(N)/(N_(0))=(1)/(10), t = ?` `lambda = (0.693)/(T)=(0.693)/(100)=0.693xx10^(-2)` years `N=N_(0)e^(-lambda t)rArr e^(-lambda t)=(N)/(N_(0))=(1)/(10)` `e^(lambda t)=10 rArr lambda t = log_(e )^(10)=2.303xxlog_(10)^(10)` `t=(2.303xx1)/(0.693xx10^(-2))=3.323xx10^(2)` `= 332.2` years |
|