Electron affinity

Moderators: Chem_Mod, Chem_Admin

704709603
Posts: 92
Joined: Wed Sep 21, 2016 2:59 pm

Electron affinity

Postby 704709603 » Wed Oct 19, 2016 9:19 am

Hi,
why is the electron affinity of Br so high when it usually has a charge of -1? Wouldn't that mean that it does not want another e-?
Thank you!
Last edited by 704709603 on Thu Oct 20, 2016 8:17 am, edited 1 time in total.

mikezargari
Posts: 20
Joined: Wed Sep 21, 2016 2:56 pm
Been upvoted: 1 time

Re: Electron affinity

Postby mikezargari » Wed Oct 19, 2016 10:57 am

Br usually has a -1 charge because it has 7 valence electrons. Electrons want to have a full valence shell so Bromine will usually "steal" an electron from an atom with less electron affinity("weaker"). With that being said if Bromine bonds with nonmetal higher up on the table it is likely that Bromine would then lose electrons to an atom with greater electron affinity. Hope this helped.

PriscillaMariscal_3F
Posts: 21
Joined: Fri Jul 15, 2016 3:00 am

Re: Electron affinity

Postby PriscillaMariscal_3F » Thu Oct 20, 2016 1:33 am

Do the noble gases have a high electron affinity even if they have a complete octet?

Ex: Comparing Ne and Cl, which has a higher electron affinity?

EmmaSaid3C
Posts: 22
Joined: Fri Jul 22, 2016 3:00 am

Re: Electron affinity

Postby EmmaSaid3C » Thu Oct 20, 2016 8:55 pm

According to the Internet, "since the noble gases already have eight electrons in their outer shells, they don't want to attract any more. Since electronegativity measures the amount of attraction between an atom and an electron, noble gases do not have electronegativity."
Therefore, Cl would have a higher electronegativity since Ne does not have electronegativity.

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

Re: Electron affinity

Postby Chem_Mod » Thu Oct 20, 2016 11:23 pm

Br usually has a charge of -1 because it has a high electron affinity. When we tabulate these values for electron affinity it is important to remember that we tabulate them for the neutral free standing atom, the fact that you commonly see Br appear in chemistry as an anion is a direct result of this electron affinity

David Sung 2H
Posts: 15
Joined: Wed Sep 21, 2016 2:56 pm

Re: Electron affinity

Postby David Sung 2H » Sun Oct 30, 2016 9:46 pm

Priscilla_Mariscal_3b wrote:Do the noble gases have a high electron affinity even if they have a complete octet?

Ex: Comparing Ne and Cl, which has a higher electron affinity?



Electron affinity is the energy released when an extra electron is added. Knowing that noble gases have a complete octet and is at its lowest energy state, it does not need more electrons and the energy released (electron affinity) would be relatively lower than that of a halide.

Ne has a higher electron affinity because energy is released when an electron is added whereas Cl has a lower electron affinity because energy must be added to the system to add an extra electron (electron affinity is negative).

Hope this helps!


Return to “Trends in The Periodic Table”

Who is online

Users browsing this forum: No registered users and 1 guest