Half Full d^5 and Full d^10 Subshells

[keyanabogan 2J]

I understand that elements with a half full or full subshell are more stable, but I don't understand when you're allowed to do this. Is it just with elements with a subshell of 3d^4 4s^2, or 3d^9 4s^2, that are able to take an electron from the s-orbital and put it in the d-orbital?

[Lexi Nadler 1H]

I'm pretty sure the exception applies to any configuration ending in d^4 or d^9. Watch out for chromium and copper!

[Ara Yazaryan 1E]

The only exceptions we are expected to know are Cu and Cr, which in this case would be 4s1 3d5 and 4s1 3d10 respectively.

[Brenton Hwee 2J]

Is there an exception for Cobalt ions too?

[Melanie_Wong_1K]

There would only be an exception for the Co^2- ion which acts like Cu. It's electron configuration would then be [Ar] 3d^10 4s^1.