Which statement correctly defines a covalent bond?

• A. A bond formed by the attraction between ions
• B. A bond formed by the transfer of electrons
• C. A bond between two non-metals sharing electrons
• D. A bond formed by metal atoms in a lattice

Answer: (C)

Sharing electrons to fill outer electron shells binds atoms together. In covalent bonds, two non-metal atoms come close enough that their atomic orbitals overlap, allowing one or more pairs of electrons to be shared between them. This sharing lets both atoms attain a more stable arrangement, often an octet, without transferring full electrons from one atom to another. The bond can be one, two, or three shared electron pairs, corresponding to single, double, or triple covalent bonds, and the electrons are concentrated between the two nuclei, holding the atoms together as a molecule. This is different from ionic bonds, where electrons are transferred to form ions held by electrostatic attraction, and from metallic bonding, where electrons are delocalized in a lattice of metal atoms. Therefore, a bond between two non-metals sharing electrons describes covalent bonding.