Octet Rule exceptions

[Celine 1F]

How do know which elements don't have to follow the octet rule?

[Kevin Antony 2B]

H, He, Li, Be, B, and Al I believe will never have a full octet. Additionally, some elements like Si, P, S, and Cl can have expanded octets. I'm pretty sure we just have to memorize what the exceptions are.

[Juliet Stephenson 4E]

Hydrogen, Helium, Lithium, and Beryllium are exceptions because they only have s orbitals. Elements that are period 3+ can also potentially expand their octet.

[Juliet Stephenson 4E]

H, He, Li, Be, B, and Al I believe will never have a full octet. Additionally, some elements like Si, P, S, and Cl can have expanded octets. I'm pretty sure we just have to memorize what the exceptions are.

What is the reasoning behind Al not being able to have a full octet?

[Deana Moghaddas 3E]

Elements beyond the 3rd period can potentially break the octet rule

[Grecia Velasco 1G]

Hydrogen, Helium, Lithium, and Beryllium are exceptions because they only have s orbitals. Elements that are period 3+ can also potentially expand their octet.

So any element besides the first 10 elements can have expanded octets?

[905416023]

The 3rd period and after I believe it is.

[Leila_4G]

Does anyone happen to know a fun/easy limerick to help memorize these?
Thanks!

[Minh Ngo 4G]

Does anyone happen to know a fun/easy limerick to help memorize these?
Thanks!

I think the trick is your periodic table since you always gonna have it. Period 3+ meaning it n =3, l=0 (s), 1 (p), 2(d). So it has that extra d orbital that it doesn't utilize. Therefore, elements in period 3+ have an expanded octet.

[Victoria Otuya 4F]

Why is it that H, He, Li, Be, B, and Al will never be a full octet?

[Giselle Littleton 1F]

Some of the elements in the d block have unfilled orbitals. So it depends on the orbital.

[ranqiao1e]

When making an exception can lower the formal charge or make it a lot more stable.

[kendal mccarthy]

Yes some examples are H, He, Li, Be, B, and Al.

[005321227]

The first four elements will never have an octet. P,Cl, and S will typically break the octet

[Nathan Rothschild_2D]

Can someone explain why these elements are exceptions?