Lewis Structure Octet Rule Exceptions

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Junghyuk_Park_1I
Posts: 34
Joined: Wed Sep 21, 2016 2:56 pm

Lewis Structure Octet Rule Exceptions

Postby Junghyuk_Park_1I » Tue Oct 25, 2016 3:24 pm

I understand that the Lewis Structures depend on formal charge and octet rule (with formal charge being more important), but I had the following question:

Which elements tend to be/can be octet exceptions (example Boron can have 3 bonds as well as other elements with expanded octets)?
Is there a way to tell?
Is there a row it begins on?

Thank you in advance.

Tara_Shooshani_3N
Posts: 29
Joined: Wed Sep 21, 2016 3:00 pm

Re: Lewis Structure Octet Rule Exceptions

Postby Tara_Shooshani_3N » Tue Oct 25, 2016 3:54 pm

H, He, Li, and Be are exceptions since they cannot hold 8 electrons.
As for elements that have expanded octets, most of the elements after Si have expanded octets since they're in the third energy level (third row of the periodic table) and have empty d orbitals. I've specifically seen a lot of P and S with expanded orbitals.

Zsanielle Moncayo 1E
Posts: 13
Joined: Wed Nov 18, 2015 3:00 am
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Re: Lewis Structure Octet Rule Exceptions

Postby Zsanielle Moncayo 1E » Tue Oct 25, 2016 5:22 pm

How do you know by how much an element can break the octet rule? For example, how do we know Phosphorus is allowed to have 5 bonds?

404757006
Posts: 20
Joined: Wed Sep 21, 2016 3:00 pm

Re: Lewis Structure Octet Rule Exceptions

Postby 404757006 » Tue Oct 25, 2016 6:01 pm

What is the best way to recognize when an element has an expanded octet? Is it only the specific elements or does it have to do with its placement on the periodic table?

nick_pantoja_3G
Posts: 25
Joined: Sat Jul 09, 2016 3:00 am

Re: Lewis Structure Octet Rule Exceptions

Postby nick_pantoja_3G » Tue Oct 25, 2016 11:15 pm

P, S, Cl can have expanded 8e-. However, Typically Cl is not a central atom as it has a high ionization energy.


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