What defines a nonpolar covalent bond?

A nonpolar covalent bond is characterized by atoms sharing electrons equally. This occurs typically when the two bonded atoms have similar or identical electronegativity values, meaning they exert equal attractive force on the shared electrons. As a result, the distribution of electron density is uniform between the two atoms, leading to no charge separation and thus no polarity.

In contrast, unequal sharing of electrons, as seen in polar covalent bonds, happens when there is a significant difference in electronegativity between the atoms involved, resulting in partial charges. Such a scenario is not applicable to nonpolar bonds, which rely on balanced sharing. Additionally, in ionic bonds, one atom completely loses electrons to another, creating a charged state, which also does not pertain to the nature of nonpolar covalent bonds.