An electron in `Li^(2+)` ion makes a transition from higher state `n_(2)` to lower state `n_(1)=6.` The emitted photons is used to ionize an electron in H-atom from 2nd excited state. The electron on leaving the H-atom has a de Broglie wavelength `lambda-12.016 "Å"`.Find the value of `n_(2).`
Note : Use `(12.016)^(2)= (150xx144)/(13.6xx11),lambda_("Å")=sqrt((150)/(KE_(eV)))`

Answer

12