Octet Rule

[Emmanuel Ogunrinde 3L]

How does an atom or molecule violate the octet rule?

[Hovik Mike Mkryan 2I]

Hello,
During lecture it was mentioned that the first four elements do not follow the octet rule and sometimes Boron satisfies its octet with 6 electrons. Also, all elements after at the quantum level 3 and after can occupy more than 8 electrons and do not follow an octet rule. Hope this helped!

[Karan Thaker 2L]

The first four elements can form less than an octet because some of them don't even have p orbitals to fill 8 electrons with such as hydrogen. They also don't form octets because they have lower formal charges with less than an octet (more stable) or simply don't have enough electrons to form an octet in any stable manner.

The elements after n=3 are able to form more than an octet as they have the expanded shells to fill electrons with so they are able to do that. They are also more stable and usually have the correct formal charge after forming multiple bonds.

[Nicholas Kull_3L]

Expanded octets, in period 3 or below, violate this rule because they can hold more electrons than 8 to have more stability and more neutral charges. These extra lone pair electrons can alter the shape too.

[LedaKnowles2E]

Expanded octets are possible for elements in period 3 and greater, because those elements have d-orbitals that extra electrons can occupy.

[Luc Lorain 1L]

Certain elements do not need to fill their octet --namely Hydrogen (which can only ever form one bond) He, Li, and Be, which contain only 1s and *some in the last two* 2s orbitals. Other than H, these elements are pretty rare to find in covalent compounds, which may lead to unfamiliarity with this trend.