An ionic compound can conduct electricity when B. it is dissolved in water.
In this state, the ions are free to move, allowing the compound to conduct electricity. In solid form (A), the ions are fixed in place within the crystal lattice and cannot move to conduct electricity. Heating just below its melting point (C) may not provide enough energy for the ions to be free to conduct electricity, and grinding the crystals into powder (D) does not allow the ions to move freely; they still remain in the solid state.