Question

Are there trends in electronegativity?

Answer 1

Absolutely! Electronegativity, conceived as the ability of an atom in a covalent bond should increase with atomic number.

Explanation:

Of course, it's not going to be that simple. Electronegativity increases across a Period, but decreases down a Group. Incomplete electron shells shield nuclear charge very ineffectively. Fluorine is the most electronegative element, because it has the greatest effective nuclear charge. As we descend a row of the Periodic Table, nuclear charge Increases, but so does shielding by inner shell electrons. You should look at tables of elemental ionization enthalpies and electron affinities to further rationalize these trends.