expanded octet in d orbital

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Hazelle Gunawan 3G
Posts: 95
Joined: Wed Sep 30, 2020 9:52 pm

expanded octet in d orbital

Postby Hazelle Gunawan 3G » Mon Nov 09, 2020 12:07 am

can someone explain how elements with a d orbital have an expanded octet? i'm a little confused on how that translates to the overall placement of electrons

Brennan McGurrr 3C
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Joined: Wed Sep 30, 2020 9:47 pm

Re: expanded octet in d orbital

Postby Brennan McGurrr 3C » Mon Nov 09, 2020 1:07 am

P-block elements with a principal quantum number (n) of 3 or more have electrons in d orbitals. In normal octet bonding, only the s and p orbitals are being shared, which is why each element is most stable with 8 valence electrons. However, to accomodate formal charge, electrons in the d orbitals can become involved in bonding to make the bonded elements more stable. These elements can form more than 4 bonds due to their electrons in d orbitals.

Samudrala_Vaishnavi 3A
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Re: expanded octet in d orbital

Postby Samudrala_Vaishnavi 3A » Mon Nov 09, 2020 8:27 am

So elements with an expanded orbital, meaning that they could potentially hold more electrons in a Lewis structure, has to do with the fact that the d-orbital allows for extra space of up to 10 valence electrons. Looking at the periodic table, we see that elements that are before Period 3 tend to have gaps where the d-block is so they can only hold up to 7 valence electrons. We would just calculate the number of valence electrons like you would for a Lewis structure before Period 3, but you will notice that they are more electron pairs that are needed, so you can add more lone pairs to the central atom.

sophie esherick 3H
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Re: expanded octet in d orbital

Postby sophie esherick 3H » Mon Nov 09, 2020 9:19 am

Only P block atoms with a principal quantum number of 3 or more can have electrons in d orbitals.This is because their azimuthal quantum number can be 2 which corresponds to a d subshell. In a normal octet, only the s and p orbitals are being filled, which is why each element is most stable with 8 valence electrons. With octet bonding, only the valence electrons in the s and p shells are shared which is why we use the octet guideline. However, to lower formal charge and create an overall more stable structure, an atom can potentially hold more than 8 electrons because it had an empty d orbital. This means that more bonds can be made. Hope this helps!

simona_krasnegor_1C
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Re: expanded octet in d orbital

Postby simona_krasnegor_1C » Mon Nov 09, 2020 9:28 am

The d-orbtial has extra space (for 10 electrons), so when an element has this orbital, it is more likely to have an expanded octet.


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