Covalent bonds form when two atoms have which characteristic?

• A. A large difference in electronegativity.
• B. A very small difference in electronegativity (complete sharing of electrons).
• C. The transfer of electrons to form ions.
• D. A bond between a metal and a nonmetal.

Answer: (B)

Covalent bonds form when two atoms have very similar electronegativities, so they share electrons rather than transfer them. When the difference in electronegativity is minimal, the shared electrons are drawn toward both atoms roughly equally, producing a covalent bond. The idea of “complete sharing of electrons” highlights that no full transfer occurs, distinguishing covalent bonds from ionic ones where electrons are transferred.

If the electronegativity difference is large, electrons are more strongly attracted to one atom, creating an ionic bond via transfer. A bond between a metal and a nonmetal typically behaves ionically for that reason.