Exceptions for Electron Configuration

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EvaLi_3J
Posts: 53
Joined: Wed Oct 02, 2019 12:16 am

Exceptions for Electron Configuration

Postby EvaLi_3J » Sun Oct 20, 2019 11:52 am

In the lecture on Friday 10/18, professor mentioned how there exists EXCEPTIONS that half full d subshells and full d subshells have lower energy. Does anyone remember what this is exception to?

Nikki Razal 1L
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Re: Exceptions for Electron Configuration

Postby Nikki Razal 1L » Sun Oct 20, 2019 11:55 am

He said the two exceptions were for the elements copper (Cu) and chromium (Cr)

Leyna Dang 2H
Posts: 104
Joined: Thu Jul 25, 2019 12:17 am

Re: Exceptions for Electron Configuration

Postby Leyna Dang 2H » Sun Oct 20, 2019 12:07 pm

I believe they were copper (Cu) and chromium (Cr). The configuration for copper would be [Ar]3d10 4s1 and chromium would be [Ar]3d5 4s1.

Haley Fredricks 1B
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Re: Exceptions for Electron Configuration

Postby Haley Fredricks 1B » Sun Oct 20, 2019 12:16 pm

The norm is that the 4s orbital would fill up before the 3d orbital, so each element would have 4s^2 before 3d. However, in both Cu and Cr, the 4s orbital is not full, while the 3d orbital is partially full or completely full (3d^5 or 3d^10) for the purposes of stability. This is why they are called exceptions.

Anokhi Patel 2B
Posts: 76
Joined: Fri Aug 09, 2019 12:17 am

Re: Exceptions for Electron Configuration

Postby Anokhi Patel 2B » Sun Oct 20, 2019 1:49 pm

For the exceptions, this is since half full d5 and full d10 subshells have lower energy. As an example he compared Titanium and Vanadium to Copper and Chromium.

805373590
Posts: 101
Joined: Wed Sep 11, 2019 12:17 am

Re: Exceptions for Electron Configuration

Postby 805373590 » Sun Oct 20, 2019 2:30 pm

exceptions for electron configurations:
Cu-(Ar)3d^10 4s^1.
Cr-[Ar] 3d5 4s1

pauline young 1L
Posts: 50
Joined: Thu Jul 11, 2019 12:15 am

Re: Exceptions for Electron Configuration

Postby pauline young 1L » Sun Oct 20, 2019 2:49 pm

the examples he gave in class were copper and chromium, however, this does not mean those elements are the only exceptions, period 5 on the periodic table follows the same trend.


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