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Copper exception

Posted: Sun Oct 28, 2018 11:53 am
by 705170809
So I understand that the 4s^2 has a higher energy level than 3d^10 which is why it comes after 3d^10 say in element Bromine, however for Copper's electron configuration its exception makes it 3d^10 and 4s^1, but the 4s^1 is still after 3d^10, even though 4s^1 has a lower energy level than 3d^10, why is this?

Re: Copper exception

Posted: Sun Oct 28, 2018 12:31 pm
by Dimitri Speron 1C
This is because it is more stable for the entire 3d subshell to be filled than to have the 4s subshell with 2 and the 3d with 9. This is pretty much just how the math happens to work out and what is experimentally observed. A parallel to this is the electronic structure of Chromium, from the same subshell (3d) which has 3d5,4s1 instead of 3d4,4s2. Having this electron configuration is just more stable.

Re: Copper exception

Posted: Sun Oct 28, 2018 3:01 pm
by AngelaZ 1J
An electron configuration with a completely full or half full 3d subshell is more stable.

Re: Copper exception

Posted: Sun Oct 28, 2018 5:35 pm
by Chem_Mod
Put the above two together for the full answer.

Re: Copper exception

Posted: Mon Oct 29, 2018 12:47 am
by Manas Jinka
An entire 3d subshell that is full is stable instead of having 2 electrons in the 4s and 9 electrons in the 3d orbital