Octet

[Brandon Tao 1K]

What is an octet, and are there exceptions to an atom isn't an octet?

[J Medina 2I]

I think in lecture Lavelle mentioned that H, He, Li, and Be are exceptions to the octet rule.

[Sjeffrey_1C]

My TA mentioned that the 8th group is composed on octets. These are noble gases I believe.

[jvera4b]

An octet would be an atom that has 8 valence electrons, noble gases all have octets. The octet rule refers to elements wanting to bond in order to reach eight valence elctrons and stability, the exceptions are H, He, Li, and Be.

[Natalie C 1K]

an octet means that an atom has 8 valence electrons, which is usually the most stable configuration for an atom. this is why some atoms are found in their most stable configuration as cations or anions, as this provides them with an octet. noble gases have an octet, which makes them the most stable. exceptions to the octet rule are H, He, Li, and Be.

[Martina]

Atoms like P, S, and Cl also can be an exception because they can accommodate more than 8 valence electrons.

[Shrayes Raman]

Octet refers to the usual number of preferred valence electrons for atoms. There are exceptions like He H and Li, but for the most part atoms just want 8 valence electrons.

[Alison Trinh 1E]

The octet rule refers to the covalent bonds that atoms share until a noble gas configuration is reached.

[J Medina 2I]

Hydrogen and Helium fill up a duplet (2 valence electrons). Other exceptions include atoms in the d-block since they have 5 orbitals allowing them to hold more than 8 outer electrons.

[Nick Lewis 4F]

What is the basis of the octet? LIke where does the logic come from and like how do we know some only want 8 when other elements want more or less? I know its the s2 and p6, but why does this mean Be, B can't have 8?

[William Chan 1D]

Filling the octet refers to the idea that most elements want to complete their valence shell.

The valence shell (for 2nd period, usually for elements after carbon) will be the s and p subshells, which will have 8 electrons total.

[EricZhao3G]

The octet rule says that elements like to bond so that each element has 8 electrons in its valence shell. Exceptions include H, He, and Li.

[Khushboo_3D]

Atoms like Boron and Aluminum are also exceptions, since they can accommodate only 6 electrons in their valence shell.

[Diana Chavez-Carrillo 2L]

So far what I have gathered from TAs and Lavelle's lectures, the exceptions include the following:
Incomplete octets (meaning it can have less than 8 electrons) are the first 4 elements on the periodic table: H, He, Li, Be, AND B, Al.
Expanded octets (meaning it can have more than 8 electrons) are elements in the d-block, P, S, and Cl.