The Earth’s crust is the major source of metals.

In a solution of an ionic compound, the movement of ions towards the opposite electrodes when electricity is passed through the solution allows the flow of electric current, contributing to the conduction of electricity.

Heat in the molten state provides the energy needed to overcome the strong electrostatic forces of attraction between the ions in the solid lattice. As a result, the ions become mobile and can freely move, facilitating the conduction of electricity.

Ionic compounds conduct electricity in the molten state. In the molten state, the electrostatic forces of attraction between the oppositely charged ions are overcome due to the heat, allowing the ions to move freely and conduct electricity.

Ionic compounds in the solid state do not conduct electricity because the movement of ions in the solid is not possible due to their rigid structure and strong electrostatic forces of attraction between the ions.