Which type of substance can conduct electricity in the liquid phase but not in the solid phase and why?
1) ionic compound
2) metallic compound
3) nonmetallic compound
4) molecular compound

ionic compound

Explanation:

In an ionic solid, all the ions are tightly held by electrostatic attraction with the neighbouring oppositely charged ion hence they are immobile. Electricity conduction by ionic substances depends on the mobility of ions. When dissolved in water, these ions are now pulled apart from each other and migrate freely. The same occurs when the crystal lattice collapses and the solid melts. Hence only the fused substance or the solution of the substance can conduct electricity.

answer; /// i do believe that the correct answer is (a) boiling