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octet exceptions

Posted: Wed Nov 06, 2019 1:45 am
by Guzman_1J
Which are the elements that can have an expanded octet and by how much? I know P is 10, S is 12, but what about the other ones

Re: octet exceptions

Posted: Wed Nov 06, 2019 9:03 am
by Justin Sarquiz 2F
The exceptions to the octet rule are P, S, and Cl because they have an unfilled d subshell. However, I do not know the maximum amount of electrons they can hold, but I do not think that it is that relevant. Just know that these three elements can have more than 8 electrons.

Re: octet exceptions

Posted: Wed Nov 06, 2019 9:49 am
by Michael Nguyen 1E
There are other exceptions that can have expanded octets beyond just P, S, and Cl. Any element that would have unfilled d-orbitals able to be used would be able to accommodate extra electrons and have an expanded octet. It's just that the first ones that are able to do this are P, S, and Cl.

Re: octet exceptions

Posted: Wed Nov 06, 2019 10:44 am
by Ariel Davydov 1C
In addition, with elements with expanded octets, the best way to determine the amount of extra electrons they typically store is through calculating its formal charge. For example, with S, if it forms four bonds with other elements, it will typically have one additional lone pair of electrons in order to keep its formal charge at zero (FC = 6 valence e - (2 lone pair e + 8 paired e/2) = 6 - (2 + 4) = 6 - 6 = 0).