The wave number of the first line of the Balmer series for a hydrogen atom is experimentally found t — Atomic Structure Chemistry Question

💡 Solution & Explanation

The wave number $\bar{ u}$ is proportional to $Z^2$. For hydrogen $Z=1$, and for $Li^{2+}$ $Z=3$. Therefore, $\bar{ u}_{Li^{2+}} = \bar{ u}_H \times Z^2 = 15200 \text{ cm}^{-1} \times (3)^2 = 15200 \times 9 = 136800 \text{ cm}^{-1}$.