Question

How is it that ionic compounds in the solid state do not conduct electricity but they do so when in molten state?

Answer 1

In the solid state, ionic compounds are held together by strong electrostatic forces, and the ions are locked in fixed positions, so they are not free to move. Therefore, they cannot conduct electricity. However, when this salt melts, the heat overcomes these forces. The constituent ions separate and become free to move, allowing the molten salt to conduct electricity.