The ratio of wavelengths of -characteristic X-rays produced when iron (Z = 26) and scandium (Z = 21) — Atomic Structure Chemistry Question

💡 Solution & Explanation

By Moseley's law, $\frac{1}{\lambda} \propto (Z-1)^2$. Ratio $\frac{\lambda_{Fe}}{\lambda_{Sc}} = \frac{(Z_{Sc}-1)^2}{(Z_{Fe}-1)^2} = \frac{(21-1)^2}{(26-1)^2} = \frac{20^2}{25^2} = \frac{400}{625} = \frac{16}{25}$. Therefore, correct answer is C.