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Octet Rule exceptions

Posted: Sun Nov 03, 2019 8:56 pm
by Celine 1F
How do know which elements don't have to follow the octet rule?

Re: Octet Rule exceptions

Posted: Sun Nov 03, 2019 8:58 pm
by 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.

Re: Octet Rule exceptions

Posted: Sun Nov 03, 2019 9:03 pm
by 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.

Re: Octet Rule exceptions

Posted: Sun Nov 03, 2019 9:05 pm
by Juliet Stephenson 4E
Kevin Antony 1J wrote: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?

Re: Octet Rule exceptions

Posted: Sun Nov 03, 2019 9:06 pm
by Deana Moghaddas 3E
Elements beyond the 3rd period can potentially break the octet rule

Re: Octet Rule exceptions

Posted: Mon Nov 04, 2019 9:30 pm
by Grecia Velasco 1G
Juliet Stephenson 4E wrote: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?

Re: Octet Rule exceptions

Posted: Mon Nov 04, 2019 9:36 pm
by 905416023
The 3rd period and after I believe it is.

Re: Octet Rule exceptions

Posted: Tue Nov 05, 2019 12:01 am
by Leila_4G
Does anyone happen to know a fun/easy limerick to help memorize these?
Thanks!

Re: Octet Rule exceptions

Posted: Tue Nov 05, 2019 1:41 am
by Minh Ngo 4G
Leila_4E wrote: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.

Re: Octet Rule exceptions

Posted: Thu Nov 07, 2019 9:05 pm
by Victoria Otuya 4F
Why is it that H, He, Li, Be, B, and Al will never be a full octet?

Re: Octet Rule exceptions

Posted: Fri Nov 08, 2019 3:10 pm
by Giselle Littleton 1F
Some of the elements in the d block have unfilled orbitals. So it depends on the orbital.

Re: Octet Rule exceptions

Posted: Fri Nov 08, 2019 9:56 pm
by ranqiao1e
When making an exception can lower the formal charge or make it a lot more stable.

Re: Octet Rule exceptions

Posted: Sun Nov 10, 2019 11:00 pm
by kendal mccarthy
Yes some examples are H, He, Li, Be, B, and Al.

Re: Octet Rule exceptions

Posted: Sun Nov 10, 2019 11:07 pm
by 005321227
The first four elements will never have an octet. P,Cl, and S will typically break the octet

Re: Octet Rule exceptions

Posted: Sun Nov 10, 2019 11:09 pm
by Nathan Rothschild_2D
Can someone explain why these elements are exceptions?