The Periodic Laws

The most conspicuous failure of quantum physics, as a theory of chemistry, is the demonstrated inability to account in detail for the observed periodic order of the elements, the single most important feature of theoretical chemistry. The importance of this failure, if not completely ignored, is routinely underplayed in elementary chemistry texts, by statements such as [61]:

“We need not dwell on these exceptions beyond noting that they occur.”

A supposedly better informed source [51] states:

“…. the 4s state, which has a higher energy than the 3d state in hydrogen, is depressed because of its low angular momentum, which causes its orbital to be large at small r, where it can feel the full nuclear attraction.”

Still, these non-explanations¹ are generally considered sufficient to rationalize all discrepancies between observed and predicted electronic configurations.