Here's why:
* Ionic Compounds: These compounds are formed by the electrostatic attraction between positively charged ions (cations) and negatively charged ions (anions).
* Solid State: In the solid state, the ions are held rigidly in a crystal lattice structure. This fixed arrangement prevents the free movement of ions, hence no electrical conductivity.
* Molten State: When melted, the ions break free from the lattice structure and become mobile. This allows them to carry electrical charge, resulting in conductivity.
Example: Sodium chloride (NaCl) is a common ionic compound. It doesn't conduct electricity in its solid form (table salt) but conducts well when melted.
