What is the order of decreasing bond length for a C-C bond composed of the following molecular orbitals?

Question

Quizplus · Accepted Answer

Molecular orbital theory predicts that in the case of three carbon atoms, there will be three molecular orbitals formed: one bonding σ orbital, one nonbonding π orbital, and one antibonding σ* orbital. The bonding σ orbital (I) is the strongest bond and has the shortest bond length. The nonbonding π orbital (II) has a weaker bond and is longer than the σ bond. The antibonding σ* orbital (III) is the weakest bond and has the longest bond length. Therefore, the order of decreasing bond length is I > II > III, which corresponds to choice B.

What Is the Order of Decreasing Bond Length for a C-C