## Expanded Octets

Sean Phen
Posts: 102
Joined: Wed Sep 30, 2020 10:01 pm

### Expanded Octets

How do you know which elements are able to have expanded octets?

Jessica Katz
Posts: 107
Joined: Wed Sep 30, 2020 10:09 pm
Been upvoted: 2 times

### Re: Expanded Octets

They are the elements that occupy enough orbitals to accommodate a larger amount of electrons around the central atom like Xe or P.

Selena Quispe 2I
Posts: 119
Joined: Wed Sep 30, 2020 10:01 pm
Been upvoted: 3 times

### Re: Expanded Octets

Expanded octets can happen for atoms in period 3 and below. This happens when you have a full octet on the atoms in the lewis dot structure but still have left over electrons. For example, BrF3 has an expanded octet. The fluorines have a complete octet and so does bromine but there are still left over electrons so the Bromine will have the four remaining electrons bonded to it giving it a total of 10 electrons (which is allowed as it is below the third period). I hope this helps!

Vanshika Bhushan 1A
Posts: 90
Joined: Wed Sep 30, 2020 9:33 pm

### Re: Expanded Octets

An element from Period 3 and below is able to expand octet by making use of its low lying d-subshell for bonding.

This means only Period 2 elements such as C, N, O and F cannot expand octet and have to obey octet rule.

Nan_Guan_1L
Posts: 84
Joined: Wed Sep 30, 2020 9:59 pm

### Re: Expanded Octets

Just to add on to the discussion above, I think it's atoms in period 3 or higher have d-orbitals in their valence shells, so they can accommodate additional electrons.

AndrewNguyen_2H
Posts: 85
Joined: Wed Sep 30, 2020 9:59 pm

### Re: Expanded Octets

Elements beyond the n=2 principal number have expanded because their electrons can move to the d orbitals.