Electronegativity
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Electronegativity
I know that electronegativity is the tendency an atom has to attract a bonding pair of electrons to itself but how do we find the electronegativity of an atom? Why is Fluorine higher than the other halogen elements? I am just a little confused on how the electronegativity trend works and why it decreases as you go down in periods.
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Re: Electronegativity
Most of the time you will not be asked to calculate the electronegativity of a specific element, but to find the difference between the electronegativity of two elements in order to determine what type of bond they will create. Generally, the electronegativity will be high if the ionization energy and electron affinity are also high, and the electronegativity will be lower if the ionization energy and electron affinity are also low. So, electronegativity generally decreases as you move down a period and increases as you move across a group in the period table. So, fluorine has the highest electronegativity among the halogens because the shared electrons will be pulled closer to it.
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Re: Electronegativity
When ionization energy and electron affinity are high, then the atom will also have a high electronegativity, and pull shared electrons toward it. This explains the periodic table trends, but we will not need to know actual values of electronegativity.
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Re: Electronegativity
Electronegativity decreases as you go down a period because the atoms have more shells of electrons, so the valence electrons are farther from the nucleus. This means that the pull on the electrons is not as strong as in the atoms closer to the top of the period.
Re: Electronegativity
There is a trend that when ionization energy and electron affinity of an element are high, it will also have a high electronegativity. Because Fluorine has both a high e affinity and a high ionization energy, it has a high electronegativity.
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Re: Electronegativity
As you go down a period, there is more and more shielding, making the nuclear charge weaker. Therefore, it is harder to pull an electron in, decreasing the electronegativity.
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Re: Electronegativity
Can someone explain how shielding works? I understand the concept as when there are more expanded shells of electrons the electrons are further away and the ones in the furthest shell are not pulled on as much, but is it the idea that the ones closer to the nucleus are "stealing" more of the charge?
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Re: Electronegativity
It decreases as you go down the group because the attraction to the nucleus decreases so there is not as much of a pull as higher up.
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Re: Electronegativity
Nick Lewis 3D wrote:Can someone explain how shielding works? I understand the concept as when there are more expanded shells of electrons the electrons are further away and the ones in the furthest shell are not pulled on as much, but is it the idea that the ones closer to the nucleus are "stealing" more of the charge?
No, I think it's that you're adding more positive charges without increasing the negativity as much so then the charge becomes more positive and that's lower electronegativity and vice versa.
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Re: Electronegativity
Nick Lewis 3D wrote:Can someone explain how shielding works? I understand the concept as when there are more expanded shells of electrons the electrons are further away and the ones in the furthest shell are not pulled on as much, but is it the idea that the ones closer to the nucleus are "stealing" more of the charge?
When electrons are further away, the effect they feel is lessened by the distance, but also because the more electrons are added, the force of electron repulsion increases, which decreases the net charge felt from the nucleus
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Re: Electronegativity
Fluorine has the highest electronegativity since it is the smallest of the halogens atoms. Bigger halogens have more electrons and thus have more electron shielding, so the force of attraction for another electron is not as high as fluorine.
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Re: Electronegativity
There are just certain periodic trends to know. In basic terms, electronegativity is mainly reliant on an atom's positive charge and the "shielding" of electrons. N is more electronegative than C because it has one more proton, allowing it to attract electrons more tightly. F is more electronegative than other halogens because if you go down the group, the electrons are in more outer shells that are farther from the nucleus, making it harder for the atom to attract electrons.
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Re: Electronegativity
Electronegativity increases as you go up and to the right of the periodic table thus why Fluorine has the highest electronegativity. Based on electron affinity and ionization energy trends this also correlates with higher electronegativity.
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