Question

Boron differs from other $IIIA$ group elements because of:

• A. it has much lesser radius
• B. difference in the penultimate shell configuration.
• C. it is covalent in its compounds
• D. it is a non metal

Answer 1

Answer: (A), (B)

The correct options are
A it has much lesser radius
B difference in the penultimate shell configuration.

Boron differs from other $IIIA$ group elements because of its small size ($88$ pm), higher elctronegativity $\left(2.0\right)$ and higher value of ionization enthalpy ($801$ kJ/mol). The high value of ionization enthalpy is due to difference in the penultimate shell configuration.