I recently encountered a question asking whether [PtCl4]2- has square planar geometry. I know that Pt has an electronic configuration of [Xe] 5d9 6s1, in the given compound Pt2+ is there, so the E.C will be [Xe] 5d8 . But I'm confused whether Pt2+ will have four pairs of electrons or three pairs of electrons and two unpaired electrons in the 5d orbital. It seems like the latter should be true because paired electrons may be harder to take out. If that is true, is it always true as a general rule that unpaired electrons are always taken out instead of paired ones if both types are there (during the formation of the oxidised form of the element)?