Which of the following molecules or ions exhibits a fractional resonance bond order of exactly ? — Chemical Bonding Chemistry Question

💡 Solution & Explanation

In the phosphate ion ($PO_4^{3-}$), the central phosphorus atom forms one double bond and three single bonds with oxygen, leading to 5 total bonds resonating over 4 equivalent oxygen positions. $B.O. = \frac{5}{4} = 1.25$.