Ionic vs. Covalent Electronegativity

[Ian Williams 2I]

Hey guys,
On Friday's lecture Dr. Lavelle talked about how, as a general rule of thumb, if the electronegativity difference is more than 2 then an ionic bond is formed and that if its less than 1.5 the bond is covalent. What if the electronegativity is between 1.5 and 2? I know that bonds possess ionic and covalent characteristics so at some level theres a grey area surrounding the two. Is this what that 0.5 represents? Molecules without strong characteristics defining them as one or the other? This seems like it would open up a whole other can of worms though.
Thanks!

[Brandon Noimany 2C]

Hi,

I think I would define the grey area between 1.5 and 2 differences in electronegativity as very highly COVALENT bonds, since ionic does mean that one of the ions fully 'steals' an electron from the other. However, I think that in that grey area it still depends, particularly when the EN differences are nearing 2, with molecules probably classified on a case-by-case basis. As I think Dr. Lavelle mentioned, these are "general' classifications that probably have more intricacies the closer you get to the borders of classification.

Hope this helps somewhat