Electronegativity is the ability of an element to attract electrons toward itself. It affects the bond by predicting if the bond is going to be a polar or a non polar bond. Compounds having a high dipole moment (Element that is bonded to an Electronegative element) tends to have a polar bond while compounds that posses a zero or no net dipole moment (C=C bond) is a non polar bond since they have the same electronegativity. 
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