Explain how magnesium is produced at the negative electrode in experiment 1.

The liquified (/molten) MgCl₂ dissociates into Mg²⁺ and Cl⁻ ions;

The Cl⁻ ions are drawn to the positive electrode (which has a deficit of electrons) where they deposit electrons since they are negatively charged;

This yields Cl atoms (these will form Cl₂ gas by covalent bonding and bubbles will be seen as this gas rises out of the liquid and it will enter the air);

These electrons will flow from the positive electrode to the negative electrode;

The Mg²⁺ ions, conversely, will be drawn to the negative electrode or cathode (which has a surplus of electrons partly from those the Cl⁻ ions lose) where they pick up electrons since they have a positive charge;

This yields pure magnesium.