Which substance(s) will be good conductors of electricity?
I. H2O (s)
II. NaCl (s)
III. NaCl (l)
IV. Au (s)
Responses
A I and II only
B III and IV only
C II and III
D All of them
D. All of them
Explanation: In a solid state, NaCl and Au are good conductors of electricity as they have free ions or electrons that can carry electric current. In a liquid state, NaCl is also a good conductor of electricity for the same reason. H2O does not conduct electricity in its pure form (s), but can conduct when it contains dissolved ions or impurities.