## Ground State Configuration 3.19

104785906
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Joined: Wed Nov 16, 2016 3:04 am

### Ground State Configuration 3.19

The question asks for the ground state configuration and # of unpaired electrons.

Part E) Ni2+, the textbook says it is [Ar] 3d8 with two unpaired electrons, but to me it makes sense for it to be [Ar] 3d6 since 3d8 IS nickel and we're given a cation. Is this because the two electrons are taken away from 4s2 instead of taking away from the D orbital?

Sarah_Wilen
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Joined: Fri Jun 23, 2017 11:39 am
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### Re: Ground State Configuration 3.19

The electron configuration for Ni is $[Ar]3d^{2}4s^{2}$. To obtain the electron configuration for Ni+2, you take off the last two electrons you see written in the e- configuration. In this case, the e- are taken off of the 4s orbital. You are left with: $[Ar]3d^{8}$ as the e- configuration for Ni+2.

Remember to always take out or add on e- to the last orbital written in the electron configuration (which is the orbitals with the highest energy).

Hope this helps!