• # question_answer Ionic radii are A)  inversely proportional to effective nuclear charge B)  inversely proportional to square of effective nuclear charge C)  directly proportional to effective nuclear charge D)  directly proportional to square of effective nuclear charge

Ionic radii $\propto \frac{1}{{{Z}_{eff}}}$ ${{Z}_{eff}}=$Effective nuclear charge This${{Z}_{eff}}$ is calculated as follows: ${{Z}_{eff}}=Z-$screening constant $(\sigma )$ This value of screening constant is based upon the number of electrons in valence shell as well as in penultimate shells.