octet rule exceptions?

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Erica Li 1C
Posts: 31
Joined: Fri Sep 28, 2018 12:17 am

octet rule exceptions?

Postby Erica Li 1C » Tue Oct 30, 2018 3:24 pm

I'm confused, are all the atoms outside of the period 2 ones able to have an expanded octet?

Courtney McHargue 1I
Posts: 56
Joined: Fri Sep 28, 2018 12:17 am

Re: octet rule exceptions?

Postby Courtney McHargue 1I » Tue Oct 30, 2018 3:41 pm

Lavelle said that elements in the third period or below are able to hold more than 8 valence electrons, typically sulfur, silicon, phosphorus and chlorine are the main ones known to have this ability.

Emilee Hosking 1D
Posts: 32
Joined: Fri Sep 28, 2018 12:17 am

Re: octet rule exceptions?

Postby Emilee Hosking 1D » Tue Oct 30, 2018 6:44 pm

Wait so periods 1 and 2 can both have more electrons than an octet? If so, are there any in the first 2 periods that can only reach an octet?

Tuong Nguyen 2I
Posts: 71
Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 1 time

Re: octet rule exceptions?

Postby Tuong Nguyen 2I » Tue Oct 30, 2018 9:13 pm

Yes elements within the 3rd period/row can have more electrons than the octet rule allows. Also, the first four elements (Hydrogen, Helium, Lithium and Beryllium) and elements in column 14 can have incomplete octets (less that 8 electrons).

LeannaPhan14BDis1D
Posts: 57
Joined: Fri Sep 28, 2018 12:16 am

Re: octet rule exceptions?

Postby LeannaPhan14BDis1D » Fri Nov 02, 2018 12:26 am

Is there a way to figure out which ones are allowed to contradict the octet rule or is it all of the ones from 3 and down.??

MadisonB
Posts: 63
Joined: Fri Sep 28, 2018 12:19 am

Re: octet rule exceptions?

Postby MadisonB » Fri Nov 02, 2018 12:52 am

As a general rule, things become more complicated in terms of an expanded octet 3rd row and down, and the first few elements are stable with only two electrons. I found a more cut and dry rule for octet rule exceptions at this link: https://saylordotorg.github.io/text_gen ... -rule.html

their explanation is as follows: "However, there are three general exceptions to the octet rule: (1) molecules, such as NO, with an odd number of electrons; (2) molecules in which one or more atoms possess more than eight electrons, such as SF 6; and (3) molecules such as BCl 3, in which one or more atoms possess less than eight electrons."


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