Question

A gas of hydrogen-like ions is prepared in a particular excited state A. It emits photons having wavelength equal to the wavelength of the first line of the Lyman series together with photons of five other wavelengths. Identify the gas and find the principal quantum number of the state A.

Answer 1

a) The gas emits 6 wavelengths, let it be in nth excited state.

=> n(n-1)/2=6=>n=4

So,  The gas is in 4^th excited state.

b) Total no.of wavelengths in the transition is 6. We have  n(n-1)/2=6 =>n=4.