Which of the following is an electron deficient molecule? — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: An electron-deficient molecule is one that contains fewer than the standard number of valence electrons required to form covalent bonds with completed octets for all atoms. Step 2: Diborane (B2H6) has only 12 valence electrons available for bonding, which is insufficient to form standard two-electron bonds for all connections. It overcomes this by utilizing 3-centre-2-electron (3c-2e) hydrogen bridge bonds. Step 3: Thus, B2H6 is a classic example of an electron-deficient molecule, matching option (b).