What defines a polar covalent bond?

A polar covalent bond is characterized by the unequal sharing of electrons between two atoms that have differing electronegativities. Electronegativity is a measure of an atom's ability to attract and hold onto electrons. In a polar covalent bond, one atom attracts the shared electrons more strongly than the other, resulting in a distribution of charge that leads to a dipole moment: one end of the bond is slightly more negative, while the other end is slightly more positive.

This unequal sharing occurs because the two atoms involved in the bond do not have the same electronegativity. For instance, in a bond between hydrogen (which has a lower electronegativity) and oxygen (which has a higher electronegativity), oxygen pulls the shared electrons closer to itself, creating a polar molecule, like water.

The other options relate to bonding types that do not meet the criteria for a polar covalent bond. For example, equal sharing of electrons describes a nonpolar covalent bond, while a bond between similar electronegativities implies that there is no significant difference in the attraction for shared electrons, which does not lead to polarity. An ionic bond specifically involves the complete transfer of electrons from one atom to another, typically between a metal and