When an ionic bond is broken, bonding electrons are

Analyze the question: It asks what happens to the bonding electrons when an ionic bond is broken. This is about heterolytic fission (heterolysis).

Concept:

• In an ionic bond, electrons have already been transferred from the electropositive atom (metal) to the electronegative atom (non-metal). For example, in NaCl, the compound is Na⁺Cl⁻.
• When the bond is broken (for example, when the compound dissolves or melts), the ions separate. The electron pair stays with the more electronegative atom, which keeps the negative charge as an anion (Cl⁻).
• In a covalent bond, by contrast, electrons are shared, and they may split evenly if the bond breaks homolytically.

Evaluating the options:

• A. Shared between participating atoms: This describes a covalent bond, not an ionic one. ✗
• B. Gained by the most electropositive atom: The electropositive atom tends to lose electrons, not gain them. ✗
• C. Gained by the most electronegative atom: The electronegative atom attracts the bonding electrons and keeps them, forming the anion. ✓
• D. Lost by both atoms: Both atoms cannot lose electrons, because the electrons have to go somewhere. ✗

**Answer: C.

Tip: Remember that the electronegative atom "wins" the electrons, both when the bond forms and when it breaks. Think of it as the atom that is "greedy" for electrons. Ionic bond breaking = heterolytic fission, where the electron pair goes to one atom, the more electronegative one.