Question

What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition, n = 4 to n = 2 of He+ spectrum?

Answer 1

For the Balmer transition, n = 4, to n = 2 in a He+ ion, we can write.

Equating equation (ii) and (i), we get

This equation gives n₁ = 1 and n = 2. Thus the transition n = 2 to n = 1 in hydrogen

atom will have same wavelength as transition, n = 4 to n = 2 in He⁺