Ionization energy vs electronegativity vs electron affinity

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Ionization energy vs electronegativity vs electron affinity

Postby Chem_Mod » Sat Sep 03, 2011 6:05 pm

Question: Can you explain the difference between ionization energy, electronegativity and electron affinity? I get them all confused, especially the last two listed.

Chem_Mod
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Re: Ionization energy vs electronegativity vs electron affin

Postby Chem_Mod » Sat Sep 03, 2011 6:06 pm

Answer: The energy necessary to detach an electron from a nucleus is called ionization energy. Electronegativity is the tendency of an atom to attract an electron in a bond that is shares with another atom. Electron affinity is the willingness of an atom to accept additional electrons. All 3 of these follow the same period trend, increases going to the right and up.

504047082
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Re: Ionization energy vs electronegativity vs electron affin

Postby 504047082 » Sun Oct 27, 2013 10:44 pm

Are the noble gases exempt from any of these trends? Such as electron affinity since they are completely full and stable?

904103354
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Re: Ionization energy vs electronegativity vs electron affin

Postby 904103354 » Wed Oct 30, 2013 10:14 pm

Noble gases are exempt from the electronegativity and electron affinity because they're stable. Electronegativity is a relative measured value for which noble gases buck the overall trend across the periodic table, since the EN of noble gases is technically zero even though noble gases do form molecules.

Unlike electronegativty, electron affinity is an actual energy value that reflects this equation:

X + e− → X− + energy (released)

Electron affinity is negligible on quantum mechanical grounds for the noble gases, since none of them ever form anions like Ne- or something like that, and because the energy involved would not be negative/released and instead would be absorbed. In other words it would take energy input to make a noble gas atom into an anion, since it's already stable and thus for the purposes of calculating it out they don't have electron affinity values.

In summary noble gases are exempt from electronegativity and electron affinity trends but not IE trends.

Bilal Ismail Ahmed 3G
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Re: Ionization energy vs electronegativity vs electron affin

Postby Bilal Ismail Ahmed 3G » Mon Oct 12, 2015 7:44 pm

I do understand why electronegativity increases as you move from left to right across a period, but I don't understand why it increases up a group. Could you please explain this?

Christian Hessenauer 2A
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Re: Ionization energy vs electronegativity vs electron affin

Postby Christian Hessenauer 2A » Sun Nov 01, 2015 11:38 am

If I understand this correctly, as you go down in each row the atom gets bigger because there are more electrons to fill each sub shell. This makes it harder to exchange electrons, but as you go up in each row the orbitals are tighter and this makes the atoms more electronegative and more ionic.

Andrew Yoon 1L
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Re: Ionization energy vs electronegativity vs electron affin

Postby Andrew Yoon 1L » Sun Nov 01, 2015 3:28 pm

Elements get more electronegative as you go up a group because there is more distance between the valence shell and the nucleus. This is because Coulomb's law shows that how strong the attraction between electrically charged particles is dependent on the distance between the particles.

704628249
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Re: Ionization energy vs electronegativity vs electron affin

Postby 704628249 » Wed Dec 02, 2015 6:50 pm

Question: Can you explain the difference between ionization energy, electronegativity and electron affinity? I get them all confused, especially the last two listed.

Electronegativity is how strongly an atom attracts a pair of electrons (a stronger pull). Ionization energy is the amount of energy needed to remove an electron. Electron affinity is how likely an atom is to gain an electron, which corresponds to electronegativity.


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