The unpaired electron in hepta-1,3,5-trienyl radical is delocalized over four carbon atoms. Draw the resonance forms to illustrate how the unpaired electron is shared among these four carbon atoms.

The positive charge in pentadienyl cation is delocalized over three carbon atoms.

(a) Draw the molecular orbitals of pentadienyl cation in order of increasing energy.

(b) How many nodes are present in the lowest and the highest energy molecular orbitals?

Answer the following questions considering the molecular orbital diagram shown:

i. List the bonding MOs and the antibonding MOs.

ii. List the symmetric MOs and antisymmetric MOs.

iii. Identify the HOMO and LUMO.

In the LCAO model for a 5-carbon conjugated system, how many bonding orbitals are typically present?

Which of the following statements about nodes in a 5-atom conjugated system is correct?