U can make the working model of electrolysis of water. It is very simple. Take water in a glass container and salt to it. Pass electric current through it. And take 2 test tube anf and dip it in the water in an inverted manner. Hydrogen and oxygen is collected vin a ratio 2:1

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
You can make a windmill.
First take four wooden card boards whose ends are flattened and the other ends are pointed.Then join them together at the top with some glue.Then make a hole not more than 1 cm or just make a pin sized hole and that will be the place for the fan.Then take a plastic fan not of much weight and fix it with a wire,so that it moves smoothly.And then finally place it on a card board large than its own size and place the model of windmill.Then place the windmill in front of a table fan so that the blades of the fan move round.