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Exceptions to the Octet Rule Question

Posted: Tue Nov 05, 2019 9:49 pm
by Bita Ghanei 1F
Are there any other exceptions besides P, S, Cl, and the first 4 elements of the periodic table?

Thanks in advance!

Re: Exceptions to the Octet Rule Question

Posted: Tue Nov 05, 2019 10:30 pm
by Sebastian Lee 1L
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.

Re: Exceptions to the Octet Rule Question

Posted: Thu Nov 07, 2019 1:05 pm
by EvaLi_3J
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".

Re: Exceptions to the Octet Rule Question

Posted: Fri Nov 08, 2019 1:40 pm
by Manav Govil 1B
Only N, C, F and O follow the octet rule. The exceptions are when radicals are involved.

Re: Exceptions to the Octet Rule Question

Posted: Sun Nov 10, 2019 10:17 am
by AmyL_3L
The elements in the third period and after can have expanded octets.

Re: Exceptions to the Octet Rule Question

Posted: Mon Nov 11, 2019 12:03 am
by Ashley R 1A
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).