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B.                 MOLECULAR ORBITAL REPRESENTATION OF BENZENE (MO THEORY)

The bond angles of 120° in benzene suggests that C atoms are sp² hybridised.  An alternative representation therefore starts with a planar framework and considers overlap of the p orbitals (p electrons).

(Simple MO rules)
Mix n x p atomic orbitals np molecular orbitals!
Remember ethene? (p 26)

The exact calculation of their position (shown below) is beyond our discussion.

Each MO can accommodate 2 electrons, so for benzene we see all electrons are paired and occupy low energy MO’s (bonding MO’s).  All bonding MO’s are filled.  Benzene is therefore said to have a closed bonding shell of delocalised p electrons and this accounts in part for the stability of benzene.