Dear,

Electronegativity is a measure of an atom's ability to attract the shared electrons of a covalent bond to itself. If atoms bonded together have the same electronegativity, the shared electrons will be equally shared. If the electrons of a bond are more attracted to one of the atoms (because it is more electronegative), the electrons will be unequally shared. If the difference in electronegativity is large enough, the electrons will not be shared at all; the more electronegative atom will "take" them resulting in two ions and an ionic bond.Imagine a game of tug-of-war. If the two teams are of equal strength, the rope stays centered. If one team is stronger, the rope is pulled in that team's direction. If one team is overwhelmingly stronger, the weaker team is no longer able to hold onto the rope and the entire rope ends up on the side of the stronger team. This is analogous to chemical bonds. If the two atoms of the bond are of equal electronegativity, the electrons are equally shared.If one atom is more electronegative, the electrons of the bond are more attracted to that atom. If one atom is overwhelmingly more electronegative than the other atom, the electrons will not be shared and an ionic bond will result.

Hope this helps!