Which transition in the spectrum will have the exact same wavelength as the transition in the hydrog — Atomic Structure Chemistry Question

💡 Solution & Explanation

For identical wavelengths, $Z^2(1/n_1^2 - 1/n_2^2)$ must be equal. For H ($Z=1$, $2\to1$): $1(1/1 - 1/4) = 3/4$. For $He^+$ ($Z=2$, $4\to2$): $4(1/4 - 1/16) = 4(3/16) = 3/4$.