Problem for a Peer Learning Session

[Abdullah2I]

9. Draw the correct electron configuration of Ni^2+ using Aufbau's Principle.

Wouldn't this be just be the 1s, 2s, 2p, 3s, 3p, and four of the 5 3d orbitals filled? If not, please explain what the right answer is. Thanks.

[Adam Enomoto 1L]

The s subshell will lose it's electrons instead of taking it from the d orbital

[Amanda Mac 1C]

Yes, you're correct. The electron configuration would be 1s^2 2s^2 2p^6 3s^2 3p^6 3d^8 because of the absence of 4s^2 due to the 2+ charge.

[Angelica Mercado 1A]

The s subshell will lose it's electrons instead of taking it from the d orbital

To expand on this, the 4s electrons are lost rather than the electrons from the d orbital because although 4s is lower in energy than 3d at first- once the 3d sublevel is filled with electrons the 4s ends up with a higher energy than 3d as the 3d sublevel gets filled. And electrons are always taken from the sublevel with the highest energy first because those electrons are the furthest from the nucleus.