Final answer:
Sp mixing occurs in boron, nitrogen, and oxygen due to the similar energies of the s and p orbitals, allowing them to form multiple bonds. However, oxygen and fluorine have a significant energy difference between their orbitals, resulting in negligible s-p mixing and no sp hybridization.
Step-by-step explanation:
The phenomenon of sp mixing occurs in boron, nitrogen, and oxygen due to the similar energies of the s and p orbitals. This mixing of orbitals results in the formation of hybrid orbitals, which allows these elements to form multiple bonds. On the other hand, oxygen and fluorine have a significant energy difference between their 2s and 2p orbitals, which leads to negligible s-p mixing. As a result, oxygen and fluorine do not exhibit sp hybridization.