2A.5 7th edition

Moderators: Chem_Mod, Chem_Admin

Schem_student
Posts: 29
Joined: Fri Sep 28, 2018 12:19 am

2A.5 7th edition

Postby Schem_student » Tue Oct 30, 2018 1:25 pm

Question 2A.5 asks for the ground state electron configuration for Cu + which is isolectronic with Ni which would have a configuration of [Ar]3d^8 4s^2 why then is the solution [Ar] 3d^10 ?

Henri_de_Guzman_3L
Posts: 88
Joined: Fri Sep 28, 2018 12:25 am

Re: 2A.5 7th edition

Postby Henri_de_Guzman_3L » Tue Oct 30, 2018 2:22 pm

Copper has a "half-filled" 4s subshell. It is a special case. Only 1 electron sits in it's 4s subshell while 10 electrons sit in it's 3d subshell. This is a special case. Therefore, Cu+ is [Ar] 3d^10

Schem_student
Posts: 29
Joined: Fri Sep 28, 2018 12:19 am

Re: 2A.5 7th edition

Postby Schem_student » Tue Oct 30, 2018 3:11 pm

Thank you ! @Henri_de_Guzman_3L I see that it is more stable as a full 3d orbital so it takes the electron from the 4s. This would then be the same then for Chromium.

Tony Chung 2I
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

Re: 2A.5 7th edition

Postby Tony Chung 2I » Tue Oct 30, 2018 5:25 pm

Cu and Cr are special cases which means that they have different electron configurations.

Henri_de_Guzman_3L
Posts: 88
Joined: Fri Sep 28, 2018 12:25 am

Re: 2A.5 7th edition

Postby Henri_de_Guzman_3L » Fri Nov 02, 2018 6:43 pm

You're welcome! I just learned in discussion today that it is the same case for Ag+ ion which sits right below it on the periodic table. Happy studying!

Michael Novelo 4G
Posts: 64
Joined: Fri Sep 28, 2018 12:28 am

Re: 2A.5 7th edition

Postby Michael Novelo 4G » Fri Nov 02, 2018 7:59 pm

Its important to remember that there are two exceptions in the first row of the d block. Cr or Chromium's configuration is [Ar]3d^5 4s^1 and the other exception is Cu or copper which has the configuration [Ar]3d^10 4s^1. I believe one of the TA's mentioned that there are more exceptions further down the periodic table but to just focus on the 1st row of the d block.


Return to “Ionic & Covalent Bonds”

Who is online

Users browsing this forum: No registered users and 1 guest