Expanded Octets

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Sean Phen
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Joined: Wed Sep 30, 2020 10:01 pm

Expanded Octets

Postby Sean Phen » Sat Nov 14, 2020 5:08 pm

How do you know which elements are able to have expanded octets?

Jessica Katz
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Re: Expanded Octets

Postby Jessica Katz » Sat Nov 14, 2020 5:13 pm

They are the elements that occupy enough orbitals to accommodate a larger amount of electrons around the central atom like Xe or P.

Selena Quispe 2I
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Re: Expanded Octets

Postby Selena Quispe 2I » Sat Nov 14, 2020 5:15 pm

Expanded octets can happen for atoms in period 3 and below. This happens when you have a full octet on the atoms in the lewis dot structure but still have left over electrons. For example, BrF3 has an expanded octet. The fluorines have a complete octet and so does bromine but there are still left over electrons so the Bromine will have the four remaining electrons bonded to it giving it a total of 10 electrons (which is allowed as it is below the third period). I hope this helps!

Vanshika Bhushan 1A
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Re: Expanded Octets

Postby Vanshika Bhushan 1A » Sat Nov 14, 2020 5:20 pm

An element from Period 3 and below is able to expand octet by making use of its low lying d-subshell for bonding.

This means only Period 2 elements such as C, N, O and F cannot expand octet and have to obey octet rule.

Nan_Guan_1L
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Re: Expanded Octets

Postby Nan_Guan_1L » Sat Nov 14, 2020 7:24 pm

Just to add on to the discussion above, I think it's atoms in period 3 or higher have d-orbitals in their valence shells, so they can accommodate additional electrons.

AndrewNguyen_2H
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Re: Expanded Octets

Postby AndrewNguyen_2H » Sat Nov 14, 2020 7:29 pm

Elements beyond the n=2 principal number have expanded because their electrons can move to the d orbitals.


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