Chromium and Copper Electron Configurations

[Jessica Urzua-1H]

For the ground state electron configurations for chromium and copper, we are supposed to put them in the form of d^5 and d^10. If we were finding electron configurations of ions, would we still try to complete a half full or full shell? How would the electron configuration look? More specifically, which orbital would we add/remove the electron to/from? Also, chromium and copper are in the 3d section; would we treat the 4d section the same as chromium and copper? Any help is appreciated!!

[Isabelle De Rego 1A]

I'm not sure about the ion part, but all of the elements under Chromium and Copper (ex: Silver, Tungsten) would have the same type of ground state configuration where you want it to be d5s1, d10s1. So Silver is going to be [Kr]4d105s1.

[Mohamad 1J]

For the ground state of Chromium and Copper, we write the configuration as 3d^5 4s^1, and 3d^10 4s^1 respectively. This is because it is more stable with a half full or full 3d shell and a half full 4s shell then it would be with an almost half full or full 3d shell and a full 4s shell. As for ions, elements in the d-block have a rule when forming cations that electrons are taken from the uppermost s shell before they are taken from the d shell. So for example, Nickel has an electron configuration of [Ar] 3d^8 4s^2, but when we form a Ni^3+ cation we see that its electron configuration is now [Ar] 3d^7. As for the rest of the d block, I believe Ag is similar to Cu and Mo is similar to Cr, but of course, professor Lavelle said we only need to know electron configurations up until n=4 so we shouldn't have to worry about that. Hope this helped!