To make potassium chloride conduct electricity, the student could dissolve it in water. This is because potassium chloride is an ionic compound that becomes dissociated into its constituent ions when dissolved in water. The potassium ions (K+) and chloride ions (Cl-) are then free to move around in the solution, which allows the solution to conduct electricity.

The student could also melt potassium chloride and then make it contact with the electrodes of a circuit. This is because when potassium chloride is melted, its ions become mobile and the molten salt can then conduct electricity.