What best describes a polar covalent bond?

A polar covalent bond is characterized by the unequal sharing of electrons between two atoms. This occurs when the two atoms involved have different electronegativities, which is a measure of an atom's ability to attract and hold onto electrons. When one atom has a higher electronegativity than the other, it attracts the shared electrons more strongly, resulting in a shift of electron density towards that atom.

As a consequence of this unequal sharing, the more electronegative atom gains a partial negative charge, while the other atom, with lower electronegativity, acquires a partial positive charge. This creates a dipole, where one end of the bond is slightly negative and the other is slightly positive, leading to the term "polar" because of the poles produced.

The other concepts do not accurately reflect the nature of a polar covalent bond. For instance, equal sharing of electrons describes a nonpolar covalent bond, where both atoms exert equal pull on the electrons. A complete transfer of electrons characterizes ionic bonds, where one atom donates its electrons to another, leading to positively and negatively charged ions. Lastly, the description of no significant interaction suggests a lack of bonding altogether, which does not apply in the context of polar covalent bonds