Electron configuration

If the answer is correct, this means the math works out that the 7s-shell valance orbitals are at an actually higher energy than the 6d or 5f orbitals. I think this might be the answer, but I'm not familiar enough with calculations to say for sure.

 

Yes, the electrons in an atom in its ground state are arranged in the orbitals from lowest energy to highest. If the 7s orbitals happen to be at a higher energy than the 6d or 5f orbitals, then the 6d and 5f orbitals would fill up before the 6s orbital fills up.