Cr and Cu exceptions

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Valeria Viera 1B
Posts: 60
Joined: Fri Apr 06, 2018 11:05 am

Cr and Cu exceptions

Postby Valeria Viera 1B » Tue May 01, 2018 6:07 pm

I understand that Cu and Cr are exceptions when it comes to electron configurations since the d orbital is not full so then electrons in the s orbital go down a level to have a balanced amount of electrons in d. Does this mean that the elements in the same group will behave similarly? Also, is it possible this same thing can happen but instead of the d orbitals not being balanced could it be the p ?

Jocelyn Fermin1J
Posts: 49
Joined: Tue Nov 14, 2017 3:01 am

Re: Cr and Cu exceptions

Postby Jocelyn Fermin1J » Tue May 01, 2018 9:53 pm

I assumed the elements in the same group as Cu and Cr will behave similarly in order to be stable, but only those under Cu have the special rule and Mo under Cr. Can someone explain this?

Also emphasizing Valeria's question, "Also, is it possible this same thing can happen but instead of the d orbitals not being balanced could it be the p ?"

KristinaNguyen_1A
Posts: 30
Joined: Fri Apr 06, 2018 11:04 am

Re: Cr and Cu exceptions

Postby KristinaNguyen_1A » Tue May 01, 2018 10:26 pm

I am not sure about this but I am assuming that, because d is the inner orbital, it will want to be filled up, while p would be the outer orbital if you think of it at 3d 4s 4p, so it does not have the need to fill up its orbital.

Mohamad 1J
Posts: 15
Joined: Mon Apr 09, 2018 1:39 pm

Re: Cr and Cu exceptions

Postby Mohamad 1J » Fri May 04, 2018 4:05 am

Yes, we do see that elements in same groups as Cr and Cu follow that same rule, or at least for n=5 level. Because we see that the electron configuration for Ag is
[Kr] 4d^10 5s^1 instead of [Kr] 4d^9 5s^2.
As for this happening in p orbitals, I am pretty sure that it is only possible for the d orbitals as the shell is so close to the next s shell. We fill the 4s shell before the 3d because it is slightly below it, but when we start to fill the 3d shell it has less energy so that's why when we write configurations 3d would come before 4s, even if 4s is filled first. P orbitals, however, are not that close in proximity to a different shell so I am pretty sure that is why it's not possible.


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