Exceptions

[Matia Kim 1B]

What are the exceptions in regards to the electronegativity pattern regarding the periodic table? Will we need to know these exceptions for the final?

[madisondesilva1c]

I think there are a few exceptions that are not in perfect order of the trend, but relatively the most electronegative elements are on the top and to the right of the periodic table. Therefore, I feel that for exam purposes this trend should be sufficient and if there would be exception, or close difference, the exam would probably note this. I would also recommend asking your TA about this to be sure, but overall the trend should be enough for the exam in my opinion and after doing the majority of the book questions, this trend is helpful enough.

[annaspain]

The exception for ionization energy is that Nitrogen has a greater ionization energy than Oxygen, even though the trend follows that the energy increases across a period. The other exception is for electron affinity. Carbon has a greater electron affinity than Nitrogen which does not follow the trend that electron affinity increases across a period.

[Rithana Srikanth 3L]

There are no major exceptions that we need to be aware of - knowing the general periodic trends should be enough.

[Karishma_1G]

The general trend in electronegativity is that it increases diagonally from the bottom left corner of the periodic table up to fluorine (the most electronegative). In terms of this general trend, hydrogen can be considered an exception since it is on the left side of the periodic table but has an electronegativity similar to that of boron and carbon rather than lithium.

[AmyL_3L]

Electronegativity trend does not include the noble gases, and Fluorine has the highest electronegativity.

[305416361]

As a previous concept mentioned, electronegativity trends do not include noble gases. Aside from that, the 4 most electronegative elements (in order) are Fluorine, Oxygen, Nitrogen, and Chlorine; I think these are the only ones that are important to memorize outside of the regular periodic trends.

[Angus Wu_4G]

Another exception is that although hydrogen is all the way to the left of the periodic table, it actually has a very similar electronegativity to carbon.