A student is designing an electrical tilt sensor to operate in a high-temperature industrial furnace. They test the electrical conductivity of magnesium chloride (MgCl2\text{MgCl}_2MgCl2) in two different physical states: as a solid at 25∘C25^\circ\text{C}25∘C and as a molten liquid at 720∘C720^\circ\text{C}720∘C.
Explain, in terms of structure and bonding, why solid magnesium chloride is a non-conductor, whereas molten magnesium chloride conducts electricity extremely well.
