This template is within the scope of WikiProject Chemistry, a collaborative effort to improve the coverage of chemistry on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.ChemistryWikipedia:WikiProject ChemistryTemplate:WikiProject ChemistryChemistry articles
I'm looking at the chart, and from Scandium onward, it shows the 3d orbital before the 4s orbital and that's incorrect, right? Don't we have to re-do the chart now, or am I not getting something? Wolffe713 (talk) 05:56, 3 December 2021 (UTC)[reply]
@Wolffe713: Both ways of writing it are fine. The order you write the orbitals makes no claim about what order they fill in. Scandium [Ar] 3d1 4s2 just means that there's one electron in the 3d and two in the 4s; it doesn't say that the 3d filled first.
Although actually, they did in a way. The configurations are: Sc3+, [Ar]; Sc2+, [Ar] 3d1; Sc+, [Ar] 3d1 4s1; Sc0, [Ar] 3d1 4s2. So if you build up a scandium atom from a bare nucleus, indeed the 3d filled first. Comparing Ca to Sc is not really that important because "add a proton and an electron, there's the next element" is a process that happens at energies high enough to ionise the atoms altogether. Double sharp (talk) 10:24, 3 December 2021 (UTC)[reply]
