What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n =

Question

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

Accepted Answer

${\bar{\upsilon}}_{H} = {\bar{\upsilon}}_{He^{+}}$

Or $R \times 1^{2}\left( \frac{1}{n_{1}^{2}} - \frac{1}{n_{2}^{2}} \right) = R \times 2^{2}\left( \frac{1}{2^{2}} - \frac{1}{4^{2}} \right)$

$\therefore n_{1} = 1\text{ and }n_{2} = 2$

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