Solid NaCl:
* Ionic Structure: Sodium chloride is an ionic compound. This means it's made up of positively charged sodium ions (Na+) and negatively charged chloride ions (Cl-) held together by strong electrostatic forces.
* Fixed Positions: In solid NaCl, these ions are arranged in a rigid, crystalline lattice structure. They are locked in fixed positions and can't move freely.
* No Free Charge Carriers: Since the ions are immobile, there are no free charges to carry an electrical current.
Liquid NaCl (Molten Salt):
* Melting & Ion Mobility: When NaCl melts, the strong electrostatic forces holding the ions together are weakened. The ions break free from their fixed positions and become mobile.
* Free Charge Carriers: These mobile ions can now move freely. When an electric potential is applied, the positive sodium ions move towards the negative electrode, and the negative chloride ions move towards the positive electrode.
* Conductivity: This movement of charged particles constitutes an electric current, making molten NaCl a good conductor of electricity.
In short:
* Solid NaCl: Fixed ions, no free charge carriers, no conductivity.
* Liquid NaCl: Mobile ions, free charge carriers, good conductivity.
