Expanded Octet

[torialmquist1F]

How do we know when it is best to give an element an expanded octet?

[Lourick Bustamante 1B]

All elements in period 3 and further have the ability to have more than 8 valence electrons.

[Aliza Ajmal 1D]

An expanded octet is due to the existence of a "d orbital" which allows for more than 8 electrons.

[Kathleen Vidanes 1E]

Phosphorus (P), Sulfur (S), and Chlorine (Cl) all have expanded octets. All of the elements following those three can have an expanded octet, as well.

[Eli Aminpour 2K]

First you need to check if the element can have an expanded octet. It should be in period three or higher (P, S, Cl, etc). If expanding the octet allows all the formal charges to become zero/ it forms a more stable molecule, than do it. Sometimes its obvious to do if there are 6 peripheral atoms and only one central atom (XeF6), other times its less obvious. Always check formal charges