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 H⁺ ion, we can write

This equation gives n₁ = 1 and n₂ = 2. Thus the transition n = 2 to n = 1 in hydrogen atom will have the same wavelength as the transition, n = 4 to n = 2 in He⁺