1. Making water conductive with Ions

2. Oxidation and reduction reactions on electrodes

3. How ions change the chemical nature of solutions

4. Hydrogen gas production and how it is produced on a large-scale in industries

We know that metals can pass electricity. Can water pass electricity? Take tap water in the beaker and make a circuit by connecting LED in series. You can use graphite rods as the electrodes. Can you make the LED glow?

The challenge is to make the LED glow brighter by adding something into the tap water. What could be added to make it possible?

The conductivity of a material is its ability to let electricity flow through it. Compare the conductivity of different solutions. You can also use some stuff from the kitchen like lemon, sugar, salt, oil, or sugar drink like coke.

For this challenge, you strictly require adult supervision. What will happen if you bring the burning matchstick near to the electrodes? Can you identify the gases which are releasing from electrodes? Let me give you a hint, hydrogen gas makes a pop sound on burning!

If you add some drops of the pH indicator in the saltwater and pass the electricity through it, the indicator starts giving different colors on electrodes. What color is appearing on the positive electrode and why?

Recall Challenges 2 and 3, you must have used salt in them. Do you think salt alone, in absence of water, can pass electricity through it? Try this one by inserting the positive and negative electrodes in the salt, and tell us what happens and why?