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Electron Affinity

Posted: Mon Oct 21, 2019 4:27 pm
by BeylemZ-1B
Can someone describe the trends in the periodic table referring to Electron Affinity? I understand that it is the energy released when an electron is added, but i do not quite understand how i would be able to qualitatively decide which elements have a higher E(ea) value.

Re: Electron Affinity

Posted: Mon Oct 21, 2019 4:46 pm
by Megan Vu 1J
For the trend in electron affinity, it shows that energy is released when e- are added to gas phase atoms. For example, X(g) + e- --> X-(g) would be defined as Electron affinity = E(X)(g) - E(X-)(g).
This is different because it uses initial - final instead of final - initial like most of other chemical problems.
This is less periodic in trend, but the high electron affinity increases the most for elements in the top right of the periodic table to group 17.

Re: Electron Affinity

Posted: Tue Oct 22, 2019 11:12 am
by Zoya Mulji 1K
going off the previous answer, there is a high electron affinity for elements in the top right of the periodic table so it follows a similar trend to ionization energy in that it decreases down and group and increases across a period. this does exclude noble gases though because adding an electron to a filled valence shell is unfavorable and energy would be required for that.

Re: Electron Affinity

Posted: Fri Oct 25, 2019 2:19 pm
by Jenna Ortiguerra 4G
Correct, electron affinity is the energy released when an electron is added. Electron affinity fits the trend in which it increases as you go up and across the period on the periodic table because these atoms have a stronger attraction between the nucleus and its electrons, thus more energy is released when an electron is added.

Re: Electron Affinity

Posted: Fri Oct 25, 2019 3:30 pm
by Aiden Metzner 2C
Atoms always want to get to a their lowest possible energy. So it makes sense that electron affinity increases as you go towards the top right of the periodic table. Atoms like halogens have high electron affinities because they will release the most energy by getting to the stable noble gas state