Which electeonic transition in `Li^(+2)` will emit photon of same energy as that emitted due to transition from ` 5^(th) ` excited state to `1^(st)` excited State in `He^(+)`.

Total number of spectral in UV region during transition from 5 ^(th) excited state to 1^(St) excited state

Total number of spectral in UV region during transition from 5 ^(th) excited state to 1^(St) excited state

In a H like sample electrons make transition from 4th excited state to 1st state then

For the hydrogen atom the energy of radiation emitted in the transitation from 4th excited state to 2nd exicited state according to Bohr 's theory is

Electrons in a sample of gas containing hydrogen-like atom (Z = 3) are in fourth excited state. When photons emitted only due to transition from third excited state to second excited state are incident on a metal plate photoelectorns are ejected. The stopping potential for these photoelectorns is 3.95 eV . now, if only photons emitted due to transition from fourth excited state to third excited state are incident on the same metal plate, the stopping potential for the emitted photoelectrons will be appoximetely equal to

What are the frequency of a photon emitted during a transition from n = 5 state to the n = 2 state in the hydrogen atom?