Expanded octets

[kristinalaudis3e]

How do I know how big expanded octets can expand?

[Marcus Lagman 2A]

Hello!

I believe an expanded octet of a central can expand to how many valence electrons it has in its outer shell. For example, phosphorus has 5 valence electrons, thus it can expand to 10 electrons with 5 lone paired electrons.

This is my take on it. If anyone has a better explanation, I would appreciate it!

[Sid Panda 3A]

Hello!

I believe an expanded octet of a central can expand to how many valence electrons it has in its outer shell. For example, phosphorus has 5 valence electrons, thus it can expand to 10 electrons with 5 lone paired electrons.

This is my take on it. If anyone has a better explanation, I would appreciate it!

I had another idea that the expanded octet would theoretically be able to expand to 16 valence electrons max. For example, let's say we have Ar, which has a e- configuration of [Ne] 3s2 3p6. If we excite one e- from each orbital to the 3d level, then in total we have 8 total orbitals with 1 e- (one s orbital + three p orbitals + four d orbitals) that are ready to bond. I've put a picture of my explanation below as well. I'm not sure if this is a likely scenario, though.


However, I think that the explanation that Marcus gave makes sense because it keeps to formal charge of the central expanded octet atom to 0. (Ex. Phosphorus with 5 bonds, no lone pairs has a formal charge of 0).