What kind of covalent bond involves unequal sharing of electrons?

• A. Ionic
• B. Nonpolar covalent
• C. Metallic
• D. Polar covalent

Answer: (D)

Unequal sharing of electrons happens when two atoms in a covalent bond have different electronegativities; the more electronegative atom pulls the shared electrons toward itself, creating a dipole with a partial negative charge on that atom and a partial positive charge on the other. That setup is a polar covalent bond. It sits between nonpolar covalent bonds (where electrons are shared equally because electronegativities are similar) and ionic bonds (where electrons are transferred, not shared). A classic example is the H–Cl bond, where chlorine’s greater electronegativity draws electron density toward itself, giving chlorine a partial negative charge and hydrogen a partial positive charge.