A compound that conducts an electric current in aqueous solution or in the molten state.

A compound that conducts an electric current in aqueous solution or in the molten state is a ionic compound.

E. g. NaCl (table salt)

Explanation:

Some examples of ionic compounds are NaCl, KF, KI, MgSO₄.

Ionic compounds are formed by positivie ions (named cations) and negative ions (named anions). The strong electrostatic atraction between cations and anions permits the formation of crystals, which are stuctures characterized by a regular pattern. In solid state the ions are in fixed positions.

In order to conduct electricity, the charged particles (cations and anions in the case of the ionic compounds) need to move freely.

Hence, since in solid state, ionic compounds do not conduct electric current. But, in molten (liquid) state or in aqueous solution, ionic compounds conduct electric current because, then, the ions move freely.