As you move down a group in the periodic table, how does the trend in electronegativity relate to atomic radius?

As you go down a group, each element adds a new electron shell, making the atom larger and the valence electrons farther from the nucleus. The greater distance and increased shielding reduce the pull the nucleus can exert on those outer electrons, so electronegativity drops. In other words, a larger atomic radius weakens the atom’s ability to attract bonding electrons. For instance, fluorine’s small radius gives it a high electronegativity, while chlorine’s larger radius makes it less electronegative. Thus, the downward trend in electronegativity is directly tied to the increasing atomic radius.