Which of the following will not conduct an electrical current?
pure water
tap water
aquarium water
ocean water

Pure water won’t  conduct electricity

Option A

Explanation:

Pure water doesn’t contain salts or impurities. It is the salts that dissociate to form ions that act as charge carriers in conducting solutions. For a medium to conduct electricity it should have carriers to carry the electrical charge.

Thus absence of charge carriers make pure water non conducting. Charge carriers in metals are electrons and in ionic solutions they are positive and negative ions.

Tap water, aquarium water and ocean water contains dissolved electrolytes. When electricity is passed through them the electrolytes dissociates into ions and these ions conduct electricity.