Why do octets expand?

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Michaela Capps 1l
Posts: 50
Joined: Thu Jul 27, 2017 3:00 am

Why do octets expand?

Postby Michaela Capps 1l » Wed Nov 15, 2017 1:02 pm

I have memorized that there can be octet expansions for elements in the 3rd period and beyond but I don't think I really understand why that is? I usually remember things better when I understand everything versus just memorizing so can someone please explain? Thanks!

Mitch Mologne 1A
Posts: 74
Joined: Fri Sep 29, 2017 7:04 am

Re: Why do octets expand?

Postby Mitch Mologne 1A » Wed Nov 15, 2017 2:05 pm

They are able to expand their valence shells by adding electrons to the d orbital!

Adriana Rangel 1A
Posts: 96
Joined: Fri Sep 29, 2017 7:04 am

Re: Why do octets expand?

Postby Adriana Rangel 1A » Wed Nov 15, 2017 4:58 pm

Nonmetal atoms in period 3 or later can expanded their valence shells because they have empty d-orbitals where they can store electrons.
For example, Sulfur e-configuration is: [Ne] 3s2 3p4. However, it has a 3d orbital available for bonding

Jessica Jones 2B
Posts: 80
Joined: Fri Sep 29, 2017 7:04 am

Re: Why do octets expand?

Postby Jessica Jones 2B » Wed Nov 15, 2017 5:04 pm

All atoms in the 3p and past that like 4p,5p,6p, etc all have access to the d orbitals and can form more bonds than just their expected amount.

Harrison Wang 1H
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

Re: Why do octets expand?

Postby Harrison Wang 1H » Wed Nov 15, 2017 7:11 pm

According to the principal quantum number (n) of period 3, the angular momentum number (l) can be 2, 1, or 0. Therefore, elements in the third period have empty d shells even though they come before elements with electrons in them already on the periodic table


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