delta + or -

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Tiffanny_Carranza_2D
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delta + or -

Postby Tiffanny_Carranza_2D » Mon Nov 09, 2020 1:15 pm

how do we know when something is delta + or -

at the end of lecture today, professor did H-o-H and he said O was delta -


how did he know?

thank you

Sarah_Hoffman_2H
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Re: delta + or -

Postby Sarah_Hoffman_2H » Mon Nov 09, 2020 1:19 pm

Because oxygen is more electronegative, the electrons in the molecule are slightly drawn towards the atom, making the O slightly negative. This draws electrons away from the H atom make that end slightly positive.

Lisa Seidl 3H
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Re: delta + or -

Postby Lisa Seidl 3H » Mon Nov 09, 2020 1:21 pm

An element will have a delta + charge if it has less valence electrons in a molecule than it should according to the periodic table. Since there're fewer electrons there is a positive charge. The opposite is also true where if there are more electrons in the molecule than listed on the periodic table, there will be a partial negative charge since there is more negative energy from an abundance of electrons.

Hope this helps!

Lily Mohtashami
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Re: delta + or -

Postby Lily Mohtashami » Mon Nov 09, 2020 1:37 pm

We know that Oxygen is delta negative because it has a greater affinity for electrons and also a greater ionization energy which means that oxygen is also more electronegative. Oxygen will then attract more electrons which will make its overall charge more negative.

Hope this helps!

Sam_Marasigan_3D
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Re: delta + or -

Postby Sam_Marasigan_3D » Mon Nov 09, 2020 1:45 pm

Delta positive donates electrons and delta negative accepts electrons.

Alara Aygen 3K
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Re: delta + or -

Postby Alara Aygen 3K » Mon Nov 09, 2020 2:00 pm

If the atom pulls the electrons it is delta negative and if the electrons are moving away from an atom it is delta positive

Eileen Quach Dis 2A
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Re: delta + or -

Postby Eileen Quach Dis 2A » Mon Nov 09, 2020 6:47 pm

I believe oxygen has a more negative charge because it's more electronegative than hydrogen. Oxygen is closer towards the right side of the periodic table than hydrogen, so that means an oxygen atom is smaller in size than a hydrogen atom, so it'll cling to electrons more tightly.

Elizabeth Kaplan 3I
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Re: delta + or -

Postby Elizabeth Kaplan 3I » Mon Nov 09, 2020 11:03 pm

Hi! We know that oxygen is delta negative because it has a higher electron affinity and electronegativity than hydrogen, meaning that it will attract, or pull more electrons to itself. This results in it being delta negative since the oxygen region has more electrons than the hydrogen region.

Faith Lee 2L
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Re: delta + or -

Postby Faith Lee 2L » Tue Nov 10, 2020 12:12 am

To add on to everyone's informative posts:

Something Dr. Lavelle mentioned in his lecture today was this relationship: Increasing difference in electronegativity → Increasing difference in charge (delta- and delta+) → Increasing ionic character of the covalent bond.

Because O has a greater electronegativity than H (electronegativity increases across a period), the electrons within a water molecule will be unequally distributed between H and O. As O is more electronegative, it will pull the shared electrons closer to itself, resulting in a delta- charge. Knowing this relationship between electronegativity and charge will be a concept that we build upon when considering ionic characters of bonds :)

Ximeng Guo 2K
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Re: delta + or -

Postby Ximeng Guo 2K » Tue Nov 10, 2020 3:23 am

unequally shared of electrons. The atom with greater electronegativity, like O in H2O, will attract the shared electrons towards it and become delta -. Since the shared electrons are closer to O, H will become less negative and thus delta +.

Kimiya Aframian IB
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Re: delta + or -

Postby Kimiya Aframian IB » Tue Nov 10, 2020 8:53 am

Tiffanny_Carranza_2D wrote:how do we know when something is delta + or -

at the end of lecture today, professor did H-o-H and he said O was delta -


how did he know?

thank you

Hi! We know that O is delta negative because it has a higher electronegativity than H does, so it will pull the electrons towards it, therefore giving it a more negative charge. It is important to remember that he was describing how covalent bonds have ionic characteristics, with the partial negative charge on the O being just that.
Hope this helps!

Inderpal Singh 2L
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Re: delta + or -

Postby Inderpal Singh 2L » Tue Nov 10, 2020 11:32 am

You would base it off the one that has the higher electronegativity! Also, remember that induced dipole moments can cause compounds such as N2 to have one nitrogen slightly more electronegative than the other.

EnricoArambulo3H
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Re: delta + or -

Postby EnricoArambulo3H » Tue Nov 10, 2020 11:48 am

When we draw a Lewis structure that consists of different atoms, one atom will be more electronegative than the other. The more electronegative atom pulls the electrons toward it, causing that atom to be partially negative (delta -). Likewise, since the partially negative atom pulls the electrons toward it, the other atom will become partially positive. Hope this helped!


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