1E.13

[Karina Koo 2H]

I'm a bit confused on how to write the e- configuration of silver. I would think it's [Kr] 4d^9 5s^2 but according to the back of the 7th edition textbook, the answer is [Kr] 4d^10 5s^1. I'm noticing that this is kind of like the exceptions of copper and chromium mentioned in class, is this an exception as well? and if so, what other exceptions should I look out for?

[Tuong Nguyen 2I]

Yeah this would be another example of that exception in electron configurations. The transition metals from Copper and and Chromium take one electron from the 4s orbital to either have a half filled 3d orbital (in the case of Chromium) or a fully filled 3d orbital (in the case of silver).

[Hailey Boehm 2H]

Yes, I agree with what was previously said about this being another exception. In general, it is more favorable for electrons to fill an orbital (like 3d) than to pack 2 electrons into 4s because it costs less energy for this configuration. This is because a completely filled or 1/2 filled d subshell is more stable than a partially filled d subshell, so an e- from the 4s orbital will generally rise to the 3d orbital in this situation.

[Mayaal_Khan_4H]

Start removing electrons from the s-orbital because the d-orbital is best stable when it is half or full-filled.