Which of the following bonds have lowest bond energy? — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Analyze the factors affecting single bond energy, such as bond order, atomic size, and electron-electron repulsion. Step 2: Oxygen and Nitrogen are small atoms with lone pairs. The O-O single bond has two lone pairs on each oxygen atom in highly compact 2p orbitals, resulting in severe lone pair-lone pair electrostatic repulsions that weaken the bond. Step 3: This interelectronic repulsion is much stronger in the O-O bond than in the N-N bond (which has only one lone pair per atom) or C-C and H-H bonds (no lone pairs), giving the O-O bond the lowest bond energy (option d).