Question

According to Moseleys law, the frequency v of the K $ \alpha $ line and the atomic number Z of the element have the relation:

• A. $ v\,\alpha \left( Z-b \right) $
• B. $ v\,\alpha {{\left( Z-b \right)}^{2}} $
• C. $ \sqrt{v}\,\alpha {{\left( Z-b \right)}^{2}} $
• D. $ v\,\alpha \frac{1}{{{\left( Z-b \right)}^{2}}} $

Answer 1

Answer: (C)

According to Moseley the frequency of emitted radiation corresponding to the transition of electron from energy level $ {{n}_{2}} $ to $ {{n}_{1}} $ is $ v=R{{(Z-b)}^{2}}\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right) $ $ \Rightarrow $ $ v\propto {{(Z-b)}^{2}} $ or $ \sqrt{v}\propto (Z-b) $