I saw a proper debate going on between answers to a question about whether the octet rule could be violated. Some people were pointing to hypervalency in period 3 elements, due to the available d-orbitals that are empty. Apparently, this interpretation has been pretty much disproven by real-life measurements of bond energy not corresponding with the bond energy that would exist in a hypothetical hypervalent molecule. But with the neat and simple explanation of hypervalency excluded, how does one explain molecules like SF6, or SO4? I suspect half-bonds are involved, but I don't even understand how a half bond can exist. One cannot split an electron in half (in this context at least), so how can a half bond exist?
Please explain to me as if I'm a High School student that's really learning more about the factory side of chemistry and is therefore not so acquainted with the more theoretical side of chemistry. Don't get me wrong, I love the theoretical side of chemistry, and anything mildly advanced within chemistry that I know is self-taught, but because of this, I have a lot of holes in knowledge and terminology. So, be painstakingly clear if you could :)