In a water molecule (H2O), one oxygen atom forms a covalent bond with each of 2 hydrogen atoms by sharing one electron pair with each hydrogen.

The oxygen atom attracts the shared electrons more strongly than the hydrogen atoms, forming polar covalent bonds.

Due to this unequal sharing of electrons, water is a polar molecule with a partially positive "pole" at the hydrogen end and a partially negative "pole" at the oxygen end.

Quiz