Conductivity of ionic compounds
Ionic compounds do not conduct electricity and heat well in the solid state. These compounds only conduct electricity when in liquid state or when dissolved in water.
Electrical conductivity depends on the presence of mobile charged particles.
Conductivity in ions is low in the solid state because the ions are locked in the lattice and unable to move. In the liquid or aqueous state, ionic compounds consist of free flowing ions.
Liquid and aqueous ionic compounds are conductors of electricity because they have mobile charge carriers (in the form of the ions).