Electronegativity vs Electron Affinity

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juliasloan_4g
Posts: 67
Joined: Fri Sep 28, 2018 12:28 am

Electronegativity vs Electron Affinity

Postby juliasloan_4g » Sun Oct 28, 2018 9:36 pm

Could someone please explain what the difference is between electronegativity and electron affinity. In lecture they seemed like the same thing and they seem to have the same trends on the periodic table. Can these terms be used interchangeably?

danicatran4
Posts: 35
Joined: Fri Sep 28, 2018 12:17 am

Re: Electronegativity vs Electron Affinity

Postby danicatran4 » Sun Oct 28, 2018 9:52 pm

Electronegativity is the tendency of an atom to attract electrons, while electron affinity is the amount of energy released when an electron is added to a neutral atom. They have the same trend (increase as you go across and decrease as you go down the periodic table).

Ana Pedreros
Posts: 62
Joined: Fri Sep 28, 2018 12:19 am

Re: Electronegativity vs Electron Affinity

Postby Ana Pedreros » Sun Oct 28, 2018 9:55 pm

They are very similar but these terms cannot be used interchangeably because electron affinity is a property of atoms, while electronegativity is a property of atoms when they form bonds with other atoms.

armintaheri
Posts: 68
Joined: Fri Sep 28, 2018 12:26 am

Re: Electronegativity vs Electron Affinity

Postby armintaheri » Sun Oct 28, 2018 9:57 pm

They are similar concepts with different applications. Electronegativity is only relevant in bonded atoms. The atom that attracts the electrons more in a bond has higher electronegativity. If the atoms are by themselves the concept of electronegativity is irrelevant.

Electron affinity is a property of a singular, unbound atom. It's a measure of how much energy is released when you add an electron to that atom. Now if you want to remove that electron, you have to put the same amount of energy back in. Therefore a higher electron affinity means it takes more energy to remove an electron from an atom. So you could say an atom with a high electron affinity wants electrons more. In that sense, it's a similar concept to electronegativity, but it applies in a different scenario.

If it helps, electronegativity and electron affinity are loosely correlated, which is what you saw with the periodic table trends. For example, fluorine, which has the highest electronegativity, also has the second highest electron affinity. The alkali metals, which have very low electronegativities, also have relatively low electron affinities. But the correlation is not perfect, which is why you should still understand the difference between the two.
Last edited by armintaheri on Sun Oct 28, 2018 10:03 pm, edited 1 time in total.

905109118
Posts: 34
Joined: Mon Oct 01, 2018 12:16 am

Re: Electronegativity vs Electron Affinity

Postby 905109118 » Sun Oct 28, 2018 9:58 pm

juliasloan_4g wrote:Could someone please explain what the difference is between electronegativity and electron affinity. In lecture they seemed like the same thing and they seem to have the same trends on the periodic table. Can these terms be used interchangeably?

The difference between the two is that electronegativity is a chemical property that shows how well an atom can attract electrons towards itself while electron affinity is defined as the amount of energy released when an electron is added to a neutral atom. I don't believe they can be used interchangeably.


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