How does electrolysis of molten sodium chloride produce sodium metal and chlorine gas?

The production of sodium metal and chlorine gas via the electrolysis of molten sodium chloride is typically achieved using a Downs cell. In this process, a mixture of sodium chloride and calcium chloride is used to lower the melting point of the salt, allowing it to be electrolyzed in a molten state.1

During electrolysis, an electric current is passed through the molten substance using two electrodes:2

• At the cathode (negative electrode): Sodium ions ($N{a}^{+}$) migrate to the cathode, where they gain electrons (reduction) to form liquid sodium metal.2
• At the anode (positive electrode): Chloride ions ($C{l}^{-}$) migrate to the anode, where they give up electrons (oxidation) to form chlorine gas ($C{l}_2$).2

This electrochemical reaction is essential for the industrial production of these elements, as sodium is highly reactive and does not occur in its free state in nature.34