Answer:
Only in molten or liquid form - because the charged particles inside the ions are free to move within the lattice
Step-by-step explanation:
Ionic substances are made up of positively charged cations and negatively charged anions, held in a 3D lattice by strong electrostatic forces of attraction between the ions.
For example, let's look at NaCl (sodium chloride).
Sodium Chloride is made up of positively charged
Na+ cations and negatively charged Cl− anions, held in a 3D lattice by strong electrostatic forces of attraction between the ions.
NaCl (sodium chloride) cannot conduct electricity in a solid form because the charged particles are present BUT held in a FIXED POSITION in the 3D lattice, so they are NOT free to move. Therefore, NaCl cannot conduct electricity in a solid form.
However, NaCl (sodium chloride) can conduct electricity in a liquid and molten form because the charged particles are free to move within the lattice, so NaCl can conduct electricity in a liquid and molten form.