Question

the shortest wavelength of H-atom in lyman series is X, then longest wavelength in Balmer series of He+ is

Answer 1

harshdhanawat001 is here to answer you ,,,,

Shortest wavelength, so highest energy is for , line that drops from infinity to Lyman series.

Energy = 13.6 *(1/n-1/infinity)

Energy = 13.6 , n=1

For He+ longest wavelength is for line drop from just immediately up 3 line or 2nd exited state.

So, energy= 13.6 (Z)2 *(1/(2)2-1/(3)2)

N=2 Balmer series

N=3 longest wavelength

Z=2 He+ ion

So, energy here is 13.6*20/36

So, it is 20/36 or 5/9 times of energy of H ion so for wavelength it is 9/5 more times than H ion wavelength so,

It is 9/5 x= wavelength of He+ ion ......,.,.,,,.,,  ,