Water has unique properties which include its strength as a solvent; its three environmental stages of solid, liquid, and gas; and its temperature regulation. these properties are due to polar covalent bonds between oxygen and hydrogen. the polar covalent bonds are a result of

Answer is: unbalanced electronegativity of the hydrogens and oxygens as they share electrons.
Oxygen has greater electronegativity than hydrogen, because of that oxygen is partially negative and hydrogen is partially positive.
Electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.