Octet Rule

[Samantha Burmester 3H]

In the lecture, Dr. Lavelle says that the Octet Rule is more of a guideline; is this because there are exceptions?

[josephperez_2C]

The octet rule applies to most atoms, but there are exceptions like hydrogen.

[405098546]

Yes there are a few exceptions to the octet rule. For example, molecules like NO have an odd number of electrons and in molecules like BCl3 not all the atoms possess 8 electrons.

[Angela Cong 3C]

The exceptions are H, He, Li, and Be since they will always be the elements giving their electrons instead of receiving them

[Saachi_Kotia_4E]

The exceptions are the first few atoms because they usually lose electrons to fill just the 1s orbital. I think other exceptions are like the example from class with SO4, where sulfur had more than 8 electrons because they went into the 3d orbital of sulfur.

[Nina Do 4L]

The first 4 elements are the ones that are an exception (along with others). The elements H, He, Li, and Be are exceptions to the octet rule because they are in the 2s orbital, meaning they can only have most 2 electrons. Here's more info on them in case you are confused: viewtopic.php?t=6008

[Saleha_Mian_3E]

I agree what everyone said, but basically the rule says in covalent bonds atoms share electrons until a noble-gas configuration is reached so it helps to check certain Lewis Structures to see the correct structures, there are exceptions like H,He,Li,Be.

[JT Wechsler 2B]

The octet rule is more of a guideline because there are exceptions to the rule like the first 4 electrons and the expanded octet if elements are in the third period or higher.