What are the octet exceptions?

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tonyhu
Posts: 57
Joined: Tue Sep 24, 2019 12:17 am

What are the octet exceptions?

Postby tonyhu » Wed Oct 30, 2019 11:21 pm

And why?

Andrew Liang 1I
Posts: 105
Joined: Fri Aug 30, 2019 12:18 am

Re: What are the octet exceptions?

Postby Andrew Liang 1I » Wed Oct 30, 2019 11:34 pm

P, S , and Cl are the common exceptions to the octet rule. They can hold more than 8 valence electrons because atom in period 3 or higher have d-orbital in valence shell that allows them to hold additional electrons

Jialun Chen 4F
Posts: 108
Joined: Sat Sep 07, 2019 12:16 am

Re: What are the octet exceptions?

Postby Jialun Chen 4F » Thu Oct 31, 2019 1:41 am

The first four elements, which are H, He, Li, and Be, are the exceptions to the octet rule.

Matthew Tsai 2H
Posts: 101
Joined: Wed Sep 18, 2019 12:20 am

Re: What are the octet exceptions?

Postby Matthew Tsai 2H » Sat Nov 02, 2019 3:10 pm

Elements beyond the third row of the periodic table are able to hold extra valence electrons beyond the octet because they have an unfilled d-orbital.

Nicholas_Gladkov_2J
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Joined: Sat Aug 17, 2019 12:17 am

Re: What are the octet exceptions?

Postby Nicholas_Gladkov_2J » Sat Nov 02, 2019 3:34 pm

n = 3 energy levels, or elements after P, have access to an empty d-orbital. Because of this accessible d-orbital, the elements are exceptions to the octet rule. Elements in group 13 (column with B, Al, etc.) are also exceptions with 3 pairs of e-, rather than an octet.

ZevMarx-Kahn3C
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Re: What are the octet exceptions?

Postby ZevMarx-Kahn3C » Sun Nov 03, 2019 4:39 pm

Nicholas_Gladkov_3H wrote:n = 3 energy levels, or elements after P, have access to an empty d-orbital. Because of this accessible d-orbital, the elements are exceptions to the octet rule. Elements in group 13 (column with B, Al, etc.) are also exceptions with 3 pairs of e-, rather than an octet.


Why are these group 13 elements exceptions?

Ayushi2011
Posts: 101
Joined: Wed Feb 27, 2019 12:17 am

Re: What are the octet exceptions?

Postby Ayushi2011 » Sun Nov 03, 2019 5:47 pm

Generally d-block elements because the d-orbital can accommodate more valence electrons.

Siddiq 1E
Posts: 106
Joined: Fri Aug 09, 2019 12:15 am

Re: What are the octet exceptions?

Postby Siddiq 1E » Sun Nov 03, 2019 5:52 pm

Past the 2p level, atoms can contain more electrons.

Megan_1F
Posts: 49
Joined: Thu Jul 25, 2019 12:16 am

Re: What are the octet exceptions?

Postby Megan_1F » Sun Nov 03, 2019 7:29 pm

Elements in the 3p block can have an expanded octet.

TheresaDsilva4A
Posts: 53
Joined: Thu Jul 25, 2019 12:17 am

Re: What are the octet exceptions?

Postby TheresaDsilva4A » Sun Nov 03, 2019 7:33 pm

Based on the homework problems, an element that is commonly associated with an expanded octet (hypervalence) is the noble gas Xenon. Boron and Aluminum are two elements that often exist in compounds with an incomplete octet. Hope this helps!

Jennifer Yang 3F
Posts: 56
Joined: Wed Sep 11, 2019 12:17 am

Re: What are the octet exceptions?

Postby Jennifer Yang 3F » Sun Nov 03, 2019 8:01 pm

Elements in group 13, like Boron, can have 3 pairs of e- instead of the octet.

504939134
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

Re: What are the octet exceptions?

Postby 504939134 » Sun Nov 03, 2019 8:09 pm

Octet exceptions are the first 4 elements in the periodic table which are; H,He,Li, and Be, as they will never have a full octet. An exception to this octet guideline are all elements after Neon, so in the 3p block and on, these elements are allowed to have more than 8 electrons, they don’t have to follow the octet guideline.


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