Which of the following materials DOES not conduct electricity?
#NaCl(s); NaCl(aq); NaCl(l)#?
Electrical conductivity depends on the passage of charged particles. In solid sodium chloride (halite) there are charged particles, but these are NOT free to move.
On the other hand, in aqueous solution or in molten sodium chloride, the ions (solvated or not) are free to move and can carry a current.