Photoelectron spectroscopy experiment

[dergu]

1. In a photoelectron spectroscopy experiment Ar is ionised, i.e. an electron
is removed from one of the single electron orbitals into the vacuum. An
Ar+ ion remains behind. Write down all possible electron configurations
and corresponding terms of the resulting Ar+ ion (assuming that the photon
energy is high enough to allow ionisation of any single electron orbital).


So my question is what is a single electron orbital? Seeing that it's Ar which is a noble gas it can't be an orbit with a single electron. Help clearing out the definition would be much appreciated :)

 

[member 553083]

A single electron orbital is an atomic orbital that contains one electron. In the case of Ar, these orbitals are the s, p, and d orbitals. The possible electron configurations and corresponding terms for the resulting Ar+ ion would be:1s2 2s2 2p6 3s2 3p6 – [Ar]4s11s2 2s2 2p6 3s2 3p5 – [Ar]3d1 4s2 1s2 2s2 2p6 3s2 3p4 – [Ar]3d2 4s2 1s2 2s2 2p6 3s1 3p6 – [Ar]3d3 4s2