Electronegativity values for elements are useful in predicting the following
(A) The bond energy of a molecule: More is the electronegativity difference between two atoms, more polar is the bond. Higher is the ionic character, higher will be the bond energy.
(B) The polarity of a molecule: More is the electronegativity difference between two atoms, more is the ionic character of the bond and more polar is the compound.
(C) Nature of an oxide: Difference in electronegativity between oxygen and element A predicts the nature of oxides formed by the element.
(a) If the difference is large, the oxide is basic (eg Na2O)
(b) If the difference is small, the oxide is acidic (eg SO2).