Page 1 of 1

ELECTRON AFFINITY

Posted: Mon Oct 30, 2017 9:35 pm
by Tim Foster 2A
How are we supposed to know how electron affinity changes as you go down a group on the periodic table? I know that (generally) electron affinity increases from left to right across the table, but how should I know that Na has a lower EA than Li, for example?

Re: ELECTRON AFFINITY

Posted: Mon Oct 30, 2017 9:41 pm
by Emily Duggan 1F
Electron affinity decreases down a group because as the atom radius increases, the valence electrons are further from the nucleus so those outer electrons feel a reduced electrostatic attraction (due to shielding of inner electrons), therefore the outer electrons are easier to remove or add. That is why the periodic trend is the same for electron affinity and ionization energy. Hope this helps!

Re: ELECTRON AFFINITY

Posted: Sat Nov 04, 2017 5:36 pm
by Shannon Wasley 2J
In relation to increasing electron affinity across a row, how would the electron affinities of the halogens compare to the electron affinities of the noble gases, if they are in the same row. For example, how would Chlorine and Argon relate in terms of electron affinity?

Re: ELECTRON AFFINITY

Posted: Sat Nov 04, 2017 8:17 pm
by Connor Kelligrew 2D
Also note that the atom wants to reach a stable, full valence shell, so whether that is easier by losing or gaining electrons will lead to a lower or higher electron affinity respectively.

Re: ELECTRON AFFINITY

Posted: Mon Nov 06, 2017 5:13 pm
by Michael Lee 2I
Are there any exceptions to the electron affinity increasing across the period?

Re: ELECTRON AFFINITY

Posted: Mon Nov 06, 2017 5:26 pm
by JonathanLam1G
Michael Lee 1I wrote:Are there any exceptions to the electron affinity increasing across the period?


The first couple elements in group 5 (N, P, As) have lower electron affinities than the group 4 counterparts in their row (C, Si, Ge), because the group 4 elements want an extra electron to complete their half p shells and become paramagnetic, while group 5 elements are pretty stable with a half-filled p shell, and therefore, wouldn't have as strong of an affinity for electrons.

Re: ELECTRON AFFINITY

Posted: Thu Nov 09, 2017 12:07 pm
by Yixin Angela Wang 2H
In response to Shannon's question, I think that in general, the noble gases should have an electron affinity of basically 0 because they already have a full valence shell and thus would not tend to try to gain or lose electrons. Halogens would have a high electron affinity because they really want to gain one electron to make a full valence shell.

Re: ELECTRON AFFINITY

Posted: Mon Nov 13, 2017 1:53 am
by Ilan Shavolian 1K
Yixin Angela Wang 1H wrote:In response to Shannon's question, I think that in general, the noble gases should have an electron affinity of basically 0 because they already have a full valence shell and thus would not tend to try to gain or lose electrons. Halogens would have a high electron affinity because they really want to gain one electron to make a full valence shell.


I think its actually less than zero because it requires energy to add an electron.