Ionic compounds conduct electricity in which state?

• A. Only when molten or dissolved.
• B. In the solid state only.
• C. In all states equally.
• D. Never conduct electricity.

Answer: (A)

Electric conduction requires mobile charge carriers. In ionic compounds, the charged particles are ions held in a rigid crystal lattice in the solid state, so they cannot move freely to carry current. When the compound is melted, the lattice breaks apart and the ions become mobile, allowing electricity to flow. Similarly, dissolving the compound in water dissociates it into ions that can move in the solution and conduct current. Therefore, ionic compounds conduct electricity only when molten or dissolved. They do not conduct in the solid state, they do not conduct in all states equally, and they do not never conduct.