Electron Configuration writing

[rkusampudi]

I just have a pretty simple question about the manner in which we write electron configuration. In lectures in was written in order of the periodic table (putting 3d after 4s) but in my discussion, we were told to order it in terms of principal quantum number. Which way is correct?

[Chem_Mod]

In class I did multiple examples that are in agreement with discussion section.
For example:

Sc: [Ar] 3d¹ 4s²

In⁺: [Kr] 4d¹⁰ 5s²

[Mirrat]

Also, when doing problems is everyone writing it like Professor Lavelle did it in class, i.e. for example px1 py1 (where x and y are subscripts) or just p2?

[Naama 1A]

It depends on the problem. If we're just writing out full electron configurations I tend not to write out all the sub-orbitals. Conceptually, though, it helps to think about the sub-orbitals in order to understand how the orbitals fill and how electrons are paired.

[Lauryn Jordan 1F]

Yesterday we were trying to write rhodium’s electron configuration and we got 2 different answers, so then we looked at the lavelle periodic table and clarified which one is correct, so for clarification, is rhodium an exception like cooper and chromium?

[Varsha Sivaganesh 1A]

For the test we will only need to know how to do the electron configurations for period 1-4, so I wouldn't worry about Rhodium! And I believe Copper and Chromium are the only exceptions we need to know about, just keep in mind that they are not the only two exceptions in the entire periodic table :)

[Lauryn Jordan 1F]

When dealing with an atom that is an ion for example S^2- is it incorrect to write it in condensed from as [Ar]?

[Adam Enomoto 1L]

I learned in high school that we can fill electron orbitals using the Aufbau principle 2 different ways. One way is you can write electron configurations with the orbitals in order of filling. The other way, which Lavelle wants us to do, is writing electron configurations in order of increasing principal quantum number. This way is where 3d10 is filled before 4s2.

[Jessica Nunez 1I]

Like others have said, putting 3d before 4s in electron configuration will help us understand how orbitals fill up. However, is it wrong if we put 4s before 3d?