What Happens If You Add One Electron to Fe3+?

[clouded.perception]

I have a question that my teacher can't answer. :(

I get that with the electronic configurations for atoms, an s shell fills before a d shell but also empties before a d shell. Okay.

So the last couple of subshells for iron are 4s2 3d6; Fe2+ would be 4s0 3d6 and Fe3+ would be 4s0 3d5.

Am I right so far?

My question is -- what happens if you add one electron to Fe3+? Which subshell does it go in? Do you get 4s0 3d6 (which violates the "s shell first" rule), or 4s1 3d5 (which gives you two different subshell configurations for Fe2+, depending on what it started as)?

 

[Snazzy]

The most stable ion is where the subshell is half-filled. For Fe 2+, [Ar]3d5 4s1 would be more stable than [Ar]4s0 3d6.

 

[Blueshift5]

I can provide a response to your question. The electronic configurations of atoms and ions are determined by the Aufbau principle, which states that electrons fill orbitals in order of increasing energy. This means that the 4s subshell has a lower energy than the 3d subshell, so it is filled before the 3d subshell. However, when it comes to removing electrons, the 3d subshell has a lower energy than the 4s subshell, so electrons are removed from the 4s subshell first.

In the case of Fe3+, the electronic configuration is 4s0 3d5. If you were to add one electron to this ion, it would go into the 4s subshell, giving you the configuration of 4s1 3d5. This is because the 3d subshell is already half-filled, making it more stable than the 4s subshell. Therefore, the Aufbau principle is still followed.

I hope this answers your question and helps to clarify the concept of subshells and transition metals. If you have any further questions, please don't hesitate to ask. Science is all about questioning and seeking answers, and as scientists, we are always happy to help others understand and learn.