According to molecular orbital (MO) theory, the twelve outermost electrons in the O₂ molecule are distributed as follows: A)12 in bonding MOs, 0 in antibonding MOs. B)10 in bonding MOs, 2 in antibonding MOs. C)9 in bonding MOs, 3 in antibonding MOs. D)8 in bonding MOs, 4 in antibonding MOs. E)7 in bonding MOs, 5 in antibonding MOs.

Question

Quizplus · Accepted Answer

According to the molecular orbital theory, the molecular orbitals for the O₂ molecule are formed by the combination of the atomic orbitals of the constituent atoms. The 12 outermost electrons will fill the molecular orbitals in a similar manner to the filling of atomic orbitals. The highest energy molecular orbital is the antibonding π2px orbital. This is followed by the antibonding π*2p y and π*2pz orbitals. The π2py and π2pz orbitals are both nonbonding orbitals. The remaining molecular orbitals are all bonding orbitals. There are four molecular orbitals that are completely filled by the 12 outermost electrons; these are the σ2 s, σ*2s, σ2pz, and σ*2pz orbitals. There are two partially filled molecular orbitals; these are the σ2px and σ*2px orbitals. Therefore, there are a total of 8 bonding MOs and 4 antibonding MOs, making the correct answer D.

According to Molecular Orbital (MO) Theory, the Twelve Outermost Electrons