solid sodium conducts electricity, why doesn't solid sodium chloride?

Answer 1

The electrical resistivity of a metallic conductor decreases gradually as the temperature is lowered. However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, on the other hand, drops abruptly to zero when the material is cooled below its "critical temperature". An electrical current flowing in a loop of superconducting wire can "persist" indefinitely with no power source. (google persistent currents in physics)

Advancements in Space exploration will depend on the success of applying superconductor technology. Just as solar panels can create energy from solar rays, so too can superconductors create electricity from the coldness of space. For example: SMES - Superconducting magnetic energy storage systems.

Answer 2

Think about how solid sodium conducts electricity. In solid sodium, the valence electron is shared between all the atoms and can move around. What happens to this in electron in sodium chloride?

Answer 3

Actually, NaCl *does* conduct electricity; albeit a *much smaller amount,* given any particular voltage.

The technical reason for this is that nearly all of sodium's "conduction band electrons" are "captured" by the chlorine atoms to form negative chlorine anions. These captured electrons have a much lower "band energy" in chlorine, and hence no longer lie in the "conduction band" and are not free to move around.

Answer 4

For the same reason that metalic copper conducts electricity and copper oxide doesn't. The particular type of bonding involved does not allow it.