1. The problem statement, all variables and given/known data What is the electron configuration for Ti+2? The answer to this question, from my homework, is [Ar]3d2, but I am not able to figure out why. 2. The attempt at a solution I originally thought the configuration was: Ti+2 = [Ar]4s2 and not: Ti+2 = [Ar]3d2 My reasoning was that if titanium itself, neutrally, is [Ar]4s23d2, then wouldn't, in this cation, taking away 2 electrons be more stable from the 3d sub-shell rather than the 4s sub-shell? Taking from the 4s sub-shell would leave 2 unpaired electrons in the 3d sub-shell, while taking from the 3d subshell would leave a complete electron pair in the 4s sub-shell, meaning more stability? Or is this thinking invalid?