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  POLAR COVALENT BOND: (IONICCHARACTER IN COVALENT BONDS):                The relative ability of a covalently bonded atom to attract shared pair of electrons more toward itself is called electro negativity. This factor increases due to increase in effective nuclear charge and decreases progressively in larger atoms. Hence electro negativity increases from left to right across a period and it decreases down the group in a periodic table. Out of non-metals fluorine is consider to be most electronegative element and cesium metal is the least electronegative. In non metals hydrogen is the least electronegative. In some cases it is almost similar. The increasing order of electro negativity in some common non metal is gain as;        CL <   N <   O < F Increasing order of electro negativity causes a greater degree of bond polarity. POLARITY IN DIATOMIC MOLECULES:           ...