NOTE: This is not a homework problem. I am a genuine mature age student is desparately trying to find an answer. Please help.


Consider the radial probability distributions of the orbitals (ie. 1s, 2s, 2p, 3s, 3p,. ) of a hydrogen atom (with one electron).


Suppose the hydrogen atom receives an extra electron and become a negative hydrogen ion with 2 electrons.


(I) Will the radial probability distributions of the orbitals hydrogen ion be different to that of the hydrogen atom?


(ii) Suppose we add more electrons to the hydrogen atom, will that change the radial probability distributions of the orbitals? (I mean causing a shift in the radial probability distribution of some orbitals because of electron-electron repulsion.)

Thank you very much for taking the time to read the question.

Well, I would say yes. The electrons themselves are attracted to the nucleus, and at the same time repelled by the other electrons.

If you add one, there will be more electrons that protons, meaning the nucleus will 'have less control' over the electrons and the latter will have a radial probability further from the nucleus. That is not as far as the 2s orbital though.

Suppose now you add more electrons. To make it easy, let's assume they first are where they should be, in the original radial probability area. After that, you start considering the replusion.

The 1s electrons will be moved a little away.
The 2s electrons will move yet a little further away.
The 2p, more, because of the building screening effect now.

As you go further, the orbitals are getting 'more further' each time, their displacement is larger than the electrons in the previous electrons in the lower orbitals.

So, there will surely be somewhere where you have electrons from an orbital in the same radial probability that a higher shell, like for example, you get the 4s electrons being at the distance originally for the 3d electrons. This is only an example, and it not necessarily true.

And this is what I assume from what I learned, I may be wrong, but that is what seems logical to me.