Question

Which one of the following has the highest bond energy?

• A. $O-O$
• B. $S-S$
• C. $Se-Se$
• D. $Te-Te$

Answer 1

The correct option is B $S-S$

1. As we move down the group atomic size increases.

2. As a result bond length increases and bond dissociation energy is inversely proportional to bond length, therefore bond dissociation energy decreases.

3. As bond dissociation energy decreases down the group therefore, the order should be
$S-S>Se-Se>O-O>Te-Te$

4. From the above order, it is clear that $S-S$ bond is the stronger covalent bond than $O-O$ as there are more lone pair- lone pair repulsion in $O-O$ due to small size of $O$ which makes the bond weak.

Conclusive statement- B