Polar Covalent VS Ionic

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Fatemah Yacoub 1F
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Polar Covalent VS Ionic

Postby Fatemah Yacoub 1F » Mon Nov 04, 2019 9:58 pm

How do you determine if a bond is polar covalent or ionic without looking at ionization energies?

905385366
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Re: Polar Covalent VS Ionic

Postby 905385366 » Mon Nov 04, 2019 10:01 pm

You can look at an elements electronegativity level. The more electronegative, the more uneven the distribution, and therefore has ionic character.

Sophia Shaka 3L
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Re: Polar Covalent VS Ionic

Postby Sophia Shaka 3L » Mon Nov 04, 2019 10:05 pm

You can try to logically reason it out looking at the electronegativity difference between the atoms in the bond. The larger the difference, the more ionic character the bond will likely express. However, without calculating electronegativity (X) using the equation X= .5(I+Ea) where I is ionization energy and Ea is electron affinity, you can't put it in one of the categories for certain. Typically, covalent bonds have X=1.5 or lower, and ionic have X=2 or higher. Lavelle stated he won't give us ions/molecules between these values.

Alexa Hernandez 3k
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Re: Polar Covalent VS Ionic

Postby Alexa Hernandez 3k » Mon Nov 04, 2019 10:38 pm

Look at the electronegativity difference between the two elements.

Leila_4G
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Re: Polar Covalent VS Ionic

Postby Leila_4G » Tue Nov 05, 2019 12:01 am

This is really helpful, thank you. I'm also having trouble remembering if the ionic radius trend is different than atomic radius trend?

Verity Lai 2K
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Re: Polar Covalent VS Ionic

Postby Verity Lai 2K » Tue Nov 05, 2019 10:14 am

The ionic radius trend is the same as the atomic radius trend. It decreases across the period and increases down the group.

Brynne Burrows 3K
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Re: Polar Covalent VS Ionic

Postby Brynne Burrows 3K » Tue Nov 05, 2019 10:28 am

Leila_4E wrote:This is really helpful, thank you. I'm also having trouble remembering if the ionic radius trend is different than atomic radius trend?


The ionic radius trend is the same as the atomic radius trend. Decreasing down and to the left.

Jillian C 4C
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Re: Polar Covalent VS Ionic

Postby Jillian C 4C » Sat Nov 09, 2019 1:06 pm

Both the ionic and atomic radius trends decrease across a period and increase down a group due to the additions of energy levels. Across a period, the energy level stays the same and protons are being added, increasing the nuclear charge.

Amanda Mei 1B
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Re: Polar Covalent VS Ionic

Postby Amanda Mei 1B » Sat Nov 09, 2019 2:02 pm

If you're given an electronegativity table, you can take the absolute value of the difference between the electronegativity values of each atom in the bond. A difference of >1.7 means the bond is ionic, 0.4-1.7 means the bond is polar covalent, and <0.4 means the bond is nonpolar covalent.

Osvaldo SanchezF -1H
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Re: Polar Covalent VS Ionic

Postby Osvaldo SanchezF -1H » Sat Nov 09, 2019 6:29 pm

There are many ways to determine whether a molecule is polar covalent or ionic. One method that is very practical is to see if the bond is between a non metal-non metal(covalent, possibly polar) or metal-non metal which is ionic. The difference in electronegative is a good way to determine this because if the difference is great enough then it will be ionic( greater difference than 2). To determine whether a covalent bond is polar or not, is to see the difference in electronegativity great enough. For example a Cl-Cl bond has an electronegative difference of 0 so you know for sure that its non-polar but if there is a distinguishable difference it will usually be same to assume that its polar covalent. You can always draw the Lewis structure to make see if the distribution of electrons is even or not.

RobertXu_2J
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Re: Polar Covalent VS Ionic

Postby RobertXu_2J » Sat Nov 09, 2019 7:04 pm

If the difference in electronegativity is greater than two, then it is ionic. If it is not ionic, look at the difference in charge between the atoms to determine if it is polar.

205389184
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Re: Polar Covalent VS Ionic

Postby 205389184 » Sun Nov 10, 2019 10:25 pm

The difference in electronegativity levels will allow you to distinguish what type of bond it is.


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