What is a polar covalent bond characterized by?

A polar covalent bond is characterized by the unequal sharing of electrons between two atoms. This occurs when one atom has a greater electronegativity than the other, which means it has a stronger tendency to attract electrons. As a result, the electrons spend more time closer to the more electronegative atom, leading to a partial negative charge on that atom and a partial positive charge on the less electronegative atom. This charge separation results in a dipole moment, which is a hallmark of polar covalent bonds.

In contrast, other types of bonding involve different behaviors regarding electron distribution. For instance, in nonpolar covalent bonds, electrons are shared equally between atoms, usually occurring between two atoms of the same element or atoms with very similar electronegativities. In ionic bonding, electrons are transferred completely from one atom to another, creating charged ions instead of sharing. Therefore, the key feature that distinguishes polar covalent bonds is indeed the unequal sharing of electrons.