CHEMISTRY COMMUNITY

Just to clarify: the energy of hybridized orbitals is an average of the normal orbitals, correct?

I wouldn't say that the energy of a hybridized orbital is the average of its contributing orbitals. Instead, I like to think about how much each orbital contributed to the hybridized orbital's energy. For example, a sp^3 orbital has 25% s-character and 75% p-character. It would make sense that the hybridized orbital's energy will be much closer to the p-orbital in energy than an average would make it because the p-orbital makes up most of its energy.

Going along with energy of hybrid orbitals, how do they compare to other non hybrid orbitals and why do they occur?

Hybrid orbitals occur because we want to essentially form more bonds. For instance, a Carbon atom, by theory, says we can form 4 bonds because we have 4 valence electrons. However, when we take a look at the electron configuration, we can see that 2 of its electrons (in the s-orbital are already paired), suggesting that it can only for 2 bonds with its 2 unpaired electrons in the p-orbital. We know that this is not true, so instead hybridization occurs to combine the orbitals to allow more bonds to form. Thus, we can 4 sp³ orbitals, allowing for 4 bonds.

I would say it is an average of the other energies. This is seen by the ideas of s character and p character. The more p character it has, the closer it will be to the p orbitals and the farther it will be from the s orbitals.