Ionic compounds in the solid state do not conduct electricity because their ions are held in a fixed, rigid lattice structure, limiting the mobility of charged particles. The strong electrostatic forces between positively and negatively charged ions lock them in place, preventing the flow of electric current. Unlike in a molten state or in a solution, where ions can move freely, the fixed arrangement of ions in the solid lattice inhibits their ability to carry an electric charge. As a result, ionic solids are insulators in their solid state and only become conductive when they undergo processes like melting or dissolving in a suitable solvent.