/sci/ - Science & Math

Posted this in another thread but no one seams to know inorganic.

Need someone to explain why the a1' orbital has a lower energy than its corresponding A1' AO while the e' MO remains at the same energy level as its corresponding AO.

My reasoning is that even though neither the E' nor A1' AOs of fluorine's 2s orbital don't have a similar enough energy to combine with the E' & A1' AOs boron, the A1' has matching symmetry since both are present in the 2s orbitals of the central & outter atoms so it can be partially stabilized, whereas the E' that comes from B comes from its 2p whereas that from F comes from its 2s so neither the symmetries nor energies match and therefore it cannot bond nor be stabilized. Is this right?

Question is on the post-it in pic-related. Need help understanding the bottom two molecular orbital's energy levels and why e' doesn't decrease in energy relative to it's atomic orbital but a1' does.