Molten sodium chloride (NaCl) conducts electricity due to the presence of (B) Free ions.
When solid NaCl (table salt) is melted and turned into a liquid state, its ionic bonds are broken, and the sodium (Na+) and chloride (Cl-) ions become mobile and free to move within the liquid. These free ions are responsible for carrying electric charge through the molten salt, allowing it to conduct electricity. In contrast, in the solid state, the ions are held in fixed positions and cannot move, making the substance a poor conductor of electricity.