Water Rainbow

In this experiment we use capillary action to move water from one glass to another. If you color the water with food coloring, you can get all the colors of the rainbow.

Although the food coloring used in this experiment is edible and therefore safe, it can still stain clothing and furniture. So be careful where you put the food coloring.

Materials you need for this experiment:

blue, red and yellow food coloring	These will be the base colors from which the other colors will then be mixed.
5 drinking glasses	In the glasses we will mix the colored water.
4 paper towels	The paper towels will suck the water from one glass to the other glass like candle wicks.

How to make the experiment:

	Place the five glasses close to each other and fill the 1st, 3rd and 5th glasses with water.
	Now add some red food coloring to the 1st glass, blue food coloring to the 3rd glass and yellow food coloring to the 5th glass and stir the mixture until the water is evenly colored. The blue food coloring is usually quite strong, which means you should only dissolve very little blue color in the water.
	Now twist the paper towels into rolls and place them in the glasses as shown in the picture so that the liquid can move from one glass to the next.
	After a short time you will see how the liquid is drawn upwards and slowly moves towards the neighboring glass due to capillary action.
	After a while there is the same amount of water in all the glasses and the two originally empty glasses now contain purple and green water.

Have fun experimenting!