Name the factors on which chemical effects produce by an electric current depends.

The water which we get from sources such as taps, hand pumps, well and ponds is good conductor of electricity. Why?

LED is used in a circuit. Explain why.

How many types of electrodes are there is in a battery.

British chemist, William Nicholson had shown that if electrodes were immersed in water and a current was passed, bubbles of oxygen and hydrogen were produced. What do your understand by bubbles of hydrogen and oxygen?