The discussion centers on comparing the energy levels of molecular orbitals, specifically the 1s antibonding orbital and the 2s bonding orbital in molecules A-A and A-B. It is established that antibonding orbitals are generally higher in energy than bonding orbitals. The construction of molecular orbital (MO) diagrams is emphasized, with the skill being taught in inorganic chemistry courses. A point of confusion arises regarding the energy levels, with one participant initially asserting that the 1s antibonding orbital is higher in energy than the 2s bonding orbital. However, this claim is later corrected, referencing a textbook that states for homonuclear diatomic molecules from hydrogen to neon, the 2s-2s bonding orbitals are indeed higher in energy than the 1s-1s antibonding orbitals.
