The H-O bond, found in water (H2O), is characterized as a polar covalent bond. This occurs because while both hydrogen and oxygen share electrons, the sharing is not equal. Oxygen is more electronegative than hydrogen, meaning it has a stronger attraction for electrons. As a result, the electrons in the H-O bond are pulled closer to the oxygen atom.
Due to this unequal sharing of electrons, the oxygen atom gets a partial negative charge (δ–) because it holds the electrons more closely, while the hydrogen atoms develop partial positive charges (δ+). Therefore, in a water molecule, we find that the bond displays a clear dipole moment, where there is a distinct distribution of charge.
In summary, the H-O bond is a polar covalent bond with the oxygen side being slightly negative and the hydrogen side being slightly positive, resulting from the difference in electronegativity between the two atoms.