Which of the following is the best conductor of electricity?

CONCEPT:

• The conductor of electricity: Those materials that allow the electric current to flow through them easily are called the conductor of electricity or good conductor of electricity.
  • For example, Silver, copper, gold, Aluminium, steel, etc.
• The bad conductor of electricity: Those materials that don't allow the electric current to flow through them easily are called bad conductors of electricity.
  • For example, Lead, Zinc, wood, etc.

EXPLANATION:

• Pure water or distilled water is a poor conductor of electricity because it does not contain any ions in it.
• For the conduction of electricity, the availability of ions is very important, and since they absent in pure water or distilled water, so they do not conduct electricity. Therefore option 1, 2, and 3 is incorrect.
• Saltwater is a good conductor of electricity because it contains ions of Na and Cl. 
• When salt is put in water, the water molecules pull the sodium and chlorine ions apart so they are floating freely and hence can conduct electricity. Therefore option 3 is correct.