In a polar covalent bond, the sharing of electrons is not equal. This is because the atoms involved in the bond have different electronegativities. Electronegativity is the ability of an atom to attract electrons. The more electronegative an atom is, the more it will attract electrons.

In a polar covalent bond, the atom with the greater electronegativity will attract the electrons more strongly. This will create a partial positive charge on the atom with the lower electronegativity and a partial negative charge on the atom with the higher electronegativity.

The difference in electronegativity between the two atoms determines the polarity of the bond. The greater the difference in electronegativity, the more polar the bond will be.

Polar covalent bonds are found in many molecules, including water, ammonia, and carbon dioxide. The polarity of these bonds is important for understanding the properties of the molecules. For example, the polarity of water molecules is responsible for its high surface tension and its ability to dissolve many substances.