Name one chemical compound which is produced by using the chemical effect of electric current.

Name two metals which are purified by using the chemical effect of current (or electrolysis).

Name two metals which are produced (or extracted) by using the chemical effect of electric current.

Name one compound which is decomposed into hydrogen and oxygen by using the chemical effect of electric current.

State whether the following statements are true or false :

(a) Rainwater is a non-conductor of electricity.

(b) A piece of fresh potato does not conduct electricity at all.