In the covalent bond between oxygen and hydrogen, the oxygen atom attracts electrons a bit more strongly than the hydrogen atoms. The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms
Because of the water molecule's bent shape and its atoms' unequal sharing of electrons, it has partial positive (δ+) and partial negative (δ-) poles. ... A hydrogen bond occurs when molecules that have hydrogen covalently bonded to oxygen, nitrogen or fluorine interact.
