[Aufbau89]

Hello I'm new and i have a question, please help me out.

It seems like a relatively simple question but I don't get how to do it.

Write electron configurations for the most stable ion formed by each of the elements Rb, Ba, and Se.

would it be just [Kr]5s¹ (for Rb), [Xe]6s² (for Ba), [Ar]4s² 3d¹⁰ 4p⁴ (for Se) ?

[Albert]

would it be just [Kr]5s¹ (for Rb), [Xe]6s² (for Ba), [Ar]4s² 3d¹⁰ 4p⁴ (for Se) ?

These are electron configurations of the elements, not their ions. For example, rubidium stablest ion is Rb⁺, which means it has one electron less than the atom. It's one because this way it reaches the same configuration of the closest noble gas (which are all very stable indeed).

[Aufbau89]

Oh, thank you very much.  I got it now, so all I have to do is write the electron configuration of the nearest noble gas right?  This makes a lot of sense, thanks alot Albert!