Electronegatvity question

[Dr. Wall$treet]

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Hey, for some reason today MCAT was on my mind(couldnt be that scores are due in two weeks!) but anyway i rememred this questoin about electronegativity, which made me mad because i rememered seeing the concept earlier that week while studying and i know theoretically F is the highest electronegativity but then after reading some more into it, in reality F is not hte most because of its super small unpolarizable size. THen on the MCAT there was a questoin.. which is the most electronegative and it listed F, Cl, Br, I And normally F would be if you went withthe theoretical trend but after reading that Cl really was.. so i didnt know. I went with F cause i didnt think MCAT would be that in depth but who knows. Anyone know this anc could help me out? thanks much!

 

[Tweetie_bird]

if you are talking about ions, then F is because it has the smallest Z (effective) charge. Could you address which ones were actually molecular, or ionic..etc?

 

[Dr. Wall$treet]

hey u must be on the board same time as me!.. i just mean the elemental F.. it is the same for hte ionic.. trends dont change. Or im pretty sure they dont. its been a month or so since i have really thought about this stuff so i forget the exactl explanation as to why F is not really the highest, however i know there was something. But yes it was hte molecular or elemtals state, not the ion.. thanks tweetie! ha

 

[14931]

electronegativity increases accross and decreases down hence flourine is the most electronegative element.

thats what i recall

 

[NIYO2K2]

I can recall that if size is not an issue then F has the highest eletronegativity. On the other hand if size is brought up then you have to look at the stability which mean which element can "hang on longer" then I think that would be I. I am not quite sure on this, so if anyone out there can correct me do so.

 

[Random Access]

Originally posted by Dr. Wall$treet
Hey, for some reason today MCAT was on my mind(couldnt be that scores are due in two weeks!) but anyway i rememred this questoin about electronegativity, which made me mad because i rememered seeing the concept earlier that week while studying and i know theoretically F is the highest electronegativity but then after reading some more into it, in reality F is not hte most because of its super small unpolarizable size. THen on the MCAT there was a questoin.. which is the most electronegative and it listed F, Cl, Br, I And normally F would be if you went withthe theoretical trend but after reading that Cl really was.. so i didnt know. I went with F cause i didnt think MCAT would be that in depth but who knows. Anyone know this anc could help me out? thanks much!

I think it's that while F has the highest electronegativity, it does not produce the strongest bonds, because it's small and doesn't polarize well.

-RA

 

[Harps]

One way to really think about electronegativity is to remember that it is an average of ionization energy and electron affinity of the element. So, elements that have both high ionization energy and electron affinity will have high electronegativity. Now, if you look at the periodic table trends, ionization energies are the highest for fluorine because it is the smallest in size (hard to take away stuff from really small elements because of nuclear forces). Its electron affinity is also high, so gaining electrons is favorable.
Therefore even if one considers size, flourine should be the most electronegative and the strength of the bonds really depends on the electronegativity of both atoms involved (not just Fluorine). HOpe this helps. I've been studying for the April MCAT🙂

 

[shamthis]

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