What is a covalent bond?

• A. The electrostatic attraction between positive nuclei and a shared pair of electrons
• B. The electrostatic attraction between opposite ions
• C. The attraction between metal ions and a sea of electrons
• D. The attraction between non-polar molecules

Answer: (A)

Covalent bonding happens when atoms share electrons so each atom can fill its outer shell. The shared electrons are attracted to the positive nuclei of both atoms, creating an electrostatic attraction between the nuclei and the shared electron pair. That described attraction is why the two atoms stick together in a molecule.

This differs from ionic bonding (where electrons are transferred and opposite ions attract) and metallic bonding (a lattice of positive ions surrounded by a “sea” of delocalized electrons). The idea of attraction between non-polar molecules refers to weaker intermolecular forces, not bonds within a molecule.