Exceptions to the octet rule

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salvadorramos3k
Posts: 72
Joined: Wed Sep 18, 2019 12:18 am

Exceptions to the octet rule

Postby salvadorramos3k » Sun Nov 03, 2019 12:25 am

Hi so I'm not sure exactly what it means when there are exceptions to the octet rule. Which elements are capable of doing this and what does this mean in terms of drawing a Lewis structure? Like, does an expanded octet mean that you could technically draw 10 electrons on the Lewis structure? Or does an expanded octet usually just imply that there will be a double/triple bond? Thanks :)

Jonathan Gong 2H
Posts: 105
Joined: Sat Jul 20, 2019 12:16 am

Re: Exceptions to the octet rule

Postby Jonathan Gong 2H » Sun Nov 03, 2019 12:29 am

Atoms in period 3 or higher have a d-orbital in their valence shell which allows them to accommodate more valence e-. In terms of drawing a Lewis Structure, the extra 2 e- would be drawn as lone pairs. Hope this helps.

Kayla Maldonado 1C
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Joined: Sat Aug 17, 2019 12:16 am
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Re: Exceptions to the octet rule

Postby Kayla Maldonado 1C » Sun Nov 03, 2019 2:06 am

How do we know how many valence electrons an element with an expanded octet has? How are lone pairs shown in a lewis dot structure?

rabiasumar2E
Posts: 108
Joined: Thu Jul 11, 2019 12:15 am

Re: Exceptions to the octet rule

Postby rabiasumar2E » Sun Nov 03, 2019 8:53 am

Kayla Maldonado 1A wrote:How do we know how many valence electrons an element with an expanded octet has? How are lone pairs shown in a lewis dot structure?


An element will always have the same number of valence electrons whether it has an expanded octet! Cl can have an expanded octet but its number of valence electrons will always be seven. Lone pairs are shown as two dots next to the element symbol and bonds are drawn as a line. Hope this helps!


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