2.43 (a) Silver

[Grace Lee 3G]

How come the ground-state electron configuration for silver is [Kr]4d^10 5s^1? I put [Kr]4d^9 5s^2 as my answer but I don't seem to understand how that's incorrect.

[Jessica Schirmer 1J]

I believe that the reason Silver is [Kr]4d^10 5s^1 is the same reason why Copper is an exception. The atom is more stable if the d orbital is completely full rather than partially full. Therefore one e- from the 5s orbital is "moved" into the 4d orbital.

[Isabelle Bautista 3H]

So can anyone confirm the exceptions, since it appears that silver is also following the exception that I thought applied only to chromium and copper?

[Clara Rehmann 1K]

Jessica is right - there are more exceptions than Cr and Cu, but those are the only two we learned about. Having 5 or 10 electrons in the d orbital is more stable than having 4 or 9, so any d-block element that ends up with 4 or 9 electrons in the d orbital will actually have 5 or 10 (and then just one in the subsequent s orbital).

[Chem_Mod]

Essentially it's hard to determine these configurations only from the things you have learn. You just need to memorize the chromium and copper case.