Answer
Ionic compounds conduct electricity when melted or dissolved in water while covalent compounds typically don't. This is because covalent compounds dissolve into molecules while ionic compounds dissolve into ions, which can conduct charge.
Step-by-step explanation
A covalent compound does not conduct electricity, either in its solid, liquid, or molten state.
Ionic compounds are able to conduct electricity only when their ions are free to move. This occurs when an ionic compound is dissolved in water, or when molten. When an ionic compound dissolves in water, the positive and negative ions dissociate and are then capable of conducting electricity. An ionic compound heated to its molten state will also conduct electricity because the ions dissociate and are free to move.