Question

Ionic radii are [CBSE AIPMT 2004]

• 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

Answer 1

The correct option is A

inversely proportional to effective nuclear charge

$Ionicradii\propto \frac{1}{Z_{eff}}$
$Z_{eff}$ $\to$ effective nuclear charge.
This $Z_{eff}$ is calculated as follows:
$Z_{eff}$ = Z - screening constant $\left(\sigma \right)$
This value of screening constant is based upon the number of electrons in valence shell as well as in penultimate shells.