A certain dye absorbs light of `lamda = 4000 Å` and then fluresces light of `5000 Å`. Assuming that under given conditions `50 %` of the absorbed energy is re-emitted out as fluorescence, calculate the ratio of number of quanta emitted out to the number of quanta absorbed.

Options

A. `(5)/(8)`
B. `(8)/(5)`
C. `(3)/(8)`
D. `(8)/(3)`

Answer

A

Explanation

(a) `E_(emit ted)= (50)/(100) xx E_(ab so rbed)`
No. of emitted photons `xx` Energy of emitted photon `= (50)/(100)`
`xx` No . Of absorbed photon xx Energy of absorbed photon.
`:. n_e xx (12400)/(5000) = (50)/(100) xx n_a xx (12400)/(4000)`
`:. (n_e)/(n_a) = (5)/(8)`.