Three energy levels P,Q,R of a certain atom are such that `E_(P)ltE_(Q)ltE_(R)`. If` lambda_(1),lambda_(2) and lambda_(3)` are the wave length of radiation to transition `RtoQ , QtoP` and `Rto P ` respectively . The correct relationship between `lambda_(1),lambda_(2) and,lambda_(3)` is

Options

A. `lambda_(1)+lambda_(2)=lambda_(3)`
B. `(1)/lambda_(3)=(1)/lambda_(3)+(1)/lambda_(2)`
C. `lambda_(3)=sqrt(lambda)_(1)lambda_(2))`
D. `(2)/(lambda_(3))=(1)/(lambda_(1))+(1)/(lambda_(2))`

Answer

B

Explanation

`E_(3)=E_(1)+E_(2) `
`(hc)/(lambda_(3))=(hc)/(lambda_(2))+(hc)/(lambda_(1)) rArr(1)/(lambda_(3))=(1)/(lambda_(2))+(1)/(lambda_(1))`