octet rule

[Jacob Puchalski 1G]

Are there any exceptions to the octet rule besides H, He, Li, & Be?

[AVerma_F19]

Yes, he hasn't covered this yet but some of the elements in Periods 3 and down can have something called an expanded octet. I think he will go over this on Friday.

[Malia Shitabata 1F]

Boron also tends to not follow the octet rule since it can be stable with only 6 valence electrons.

[McKenna_4A]

Yes, lager elements have larger ionic radii, meaning less interference from the positivity charged nucleus. Even noble gasses, like Xenon, can form up to 6 bonds.

[Shutong Hou_1F]

There are many exceptions to the octet rule. The octet rule works mainly well for elements in the first three periods, because they don't have d-orbitals. Since the 4th period, the electron cloud become relatively big (having d-orbitals), therefore allowing electrons more than eight as valence electrons. In drawing Lewis Structure diagrams, elements since 4th period could have more than 8 valence electrons.

[Junwei Sun 4I]

Yes besides H, He, Li and Be there are other exceptions to the octet rule. For example boron. When boron bounds with three fluorine atoms boron only gets six electrons instead of eight. And there's also something called expanded octet, which is when a central atom in a lewis structure can have more than eight electrons (four bonds). He hasn't gone over it in class but basically the reason why there can be an expanded octet is because of the d-orbitals.

[Madeline Phan 1E]

How do you know which elements are able to have an expanded octet?