Which of the following share all their 6 valence electrons and why?

Question

oxygen. sulfur, seleium , tellenium, pollonium
thanx in advance

Answer 1

All but oxygen share all six of their valence electrons. So there are SO3, SeO3, TeO3, and PoO3. One explation in the valence bond theory is that these elements (but not oxygen) are able to involve their d-orbitals.

Answer 2

Lancenigo di Villorba (TV), Italy

Your quaetion interests the Chemical Elements belonging to "p"-Block, more clearly in GROUP 16.
Among these ones, POLONIUM results the lonely METAL, so it may undergo a Chemical Oxidation leading it to share all ITS OWN ELECTRON's OUTERMOST SHELL (e.g. six ones).

I hope this could be clear.