Exceptions to the Octet Rule Question

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Bita Ghanei 1F
Posts: 60
Joined: Thu Feb 28, 2019 12:15 am

Exceptions to the Octet Rule Question

Postby Bita Ghanei 1F » Tue Nov 05, 2019 9:49 pm

Are there any other exceptions besides P, S, Cl, and the first 4 elements of the periodic table?

Thanks in advance!

Sebastian Lee 1L
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Joined: Fri Aug 09, 2019 12:15 am
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Re: Exceptions to the Octet Rule Question

Postby Sebastian Lee 1L » Tue Nov 05, 2019 10:30 pm

YES. Basically, any element in the 3rd row/period of the periodic table and beyond can have an expanded octet because they have access to the d orbital. For example, Xe (a noble gas) can make bonds and break the octet rule because it has free electron real estate in the 5d orbital.

EvaLi_3J
Posts: 53
Joined: Wed Oct 02, 2019 12:16 am

Re: Exceptions to the Octet Rule Question

Postby EvaLi_3J » Thu Nov 07, 2019 1:05 pm

Any element in and after the third period could have exceptions. The way you deal with the exceptions while drawing Lewis structure is basically make each atom an octet firstm and then attach the extra electrons onto the "exception atoms".

Manav Govil 1B
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Joined: Sat Sep 07, 2019 12:19 am

Re: Exceptions to the Octet Rule Question

Postby Manav Govil 1B » Fri Nov 08, 2019 1:40 pm

Only N, C, F and O follow the octet rule. The exceptions are when radicals are involved.

AmyL_3L
Posts: 50
Joined: Fri Aug 09, 2019 12:17 am

Re: Exceptions to the Octet Rule Question

Postby AmyL_3L » Sun Nov 10, 2019 10:17 am

The elements in the third period and after can have expanded octets.

Ashley R 1A
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Joined: Sat Aug 24, 2019 12:16 am

Re: Exceptions to the Octet Rule Question

Postby Ashley R 1A » Mon Nov 11, 2019 12:03 am

Boron is also an exception to the octet rule as it can have 6 electrons and be stable. BH3 is an example of this exception. This occurs because Boron has 3 valence electrons to begin with, and has a stable Formal Charge of 0 when it has three covalent bonds (B-H in this case).


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