Do ionic compounds conduct electricity when solid?

• A. Yes
• B. No
• C. Only at high temperature
• D. Only in a solvent

Answer: (B)

The ability to conduct electricity depends on having charges that can move. In a solid ionic compound, the ions form a rigid lattice and are held in place by strong electrostatic forces, so they can’t drift when a voltage is applied. That means no current can flow. When the compound is melted, or when it is dissolved in water, the lattice breaks apart and the ions become free to move, carrying charge and allowing electricity to flow. So, ionic compounds do not conduct as solids, but they do conduct when molten or in solution. (Note: there are some special solid ionic conductors, but that’s not the usual case.)