Other exceptions

[Kainath Kamil Dis 2K]

I remember Dr. Lavelle talked about 2 exceptions regarding the D orbital which were Chromium being 3d5 4s1 and Ag being 3d10 4s2. Are there any other exceptions? I was doing the suggested problems and it seems that Mo, (but not W or Sg) and Cu, Au (but not Rg), followed different rules? Are these exceptions ones I should take note of? Are there more?

[Autumn Jackson Dis 1J]

Yes, all elements that are right before a full d5 or full d10 have this exception. So that would be Cr, Mo, Cu Ag and Au. I believe because W and Sg involve f-orbitals, their configuration is different. Rg is still in a speculative phase, on wikipedia, the listed e configuration says "predicted"

[Omar Alami 3H]

Hi, yes you are correct there are more, but Lavelle said on the lecture in friday that we would only deal with 3d orbital, so maybe thats why he only referred to those. It wouldn't hurt to know the others as they also follow the same rules as Chromium for example.

[Lisa Ramos 1C]

I went to a UA session about this and the UA had said that the main exceptions were Chromium and Copper, though I'm sure that there are more that apply. I believe it's a symmetry thing that happens if there's a situation where 3d can be filled with 5 single electrons or 10 doubles instead of filling up the 4s orbital.