A hypothetical universe

Hi everyone,

I'm currently designing an exercise for students for a website, which involves them sorting unfamiliar elements from an "alternate universe" into a periodic table of their own design.

I'm not a chemistry specialist, and I've been a bit overambitious with my current design: orbitals hold 3 rather than 2 electrons! I seem to have hit a bit of a wall - in this universe, would the oxygen-like element be more likely to have 0 or 1 electrons in its last "2p-equivalent" orbital? Would it even be feasible for an oxygen-like element to exist? I mean, I think it would be sensible to have an element behaving like oxygen where it has 2 electrons in each of its "2p" orbitals. In which case, how might the element to the left of it behave?

If this is going to be too complicated, I might just downgrade to even electron shell numbers...