The electron configuration of scandium
The IB accepts either [Ar]4s23d1 or [Ar]3d14s2 as the correct electron configuration for scandium. This page is based on an academic paper I had published in Foundations of Chemistry in 2021 that questions the experimental evidence and assumptions made that the 3d level is lower than the 4s level in scandium. (Image of scandium from Scandium International Mining Corps) There is some doubt about the correct electron...