Food colour – blue
Draw clouds and sun on the upper part of the bottle. Draw land and water on the lower part, using the marker. Allow it to dry.
Take half glass of water.
Add a few drops of blue food colouring into it and mix well.
Pour the blue coloured water into the bottle.
Place the bottle by a window and observe what happens over a few hours.
How does it work?
When the bottle is placed by the window, the sun shine heats the water in the bottle. Part of the water in the bottle turns into water droplets and sticks to the upper half of the bottle. These droplets slowly drip down to the bottom half and this cycle continues. This experiment helps to understand how the water cycle occurs.
Water cycle is the continuous process by which water is circulated throughout the earth and the atmosphere. The sun heats up the water on the ground, causing it to evaporate. The water turns into steam or vapour and goes into the air. When the water vapour hits the cooler air, it changes back into its liquid form and creates clouds. This is called as condensation. When the clouds become heavy, water falls back onto the ground, in the form of rain or precipitation.