To complete this experiment, first place the six cups in a row and fill up the 1st, 3rd, and 5th cups with water until they are ½ full.
Add 4 drops of food colouring as follows:First cup - 4 drops of red food colouringThird cup - 4 drops of yellow food colouringFifth cup - 4 drops of blue food colouring
You could leave the cups in a row or arrange in a circle. If arranging in a circle, the first cup should be the red cup, followed by an empty cup, the third cup is the yellow cup, the fourth cup is empty. The fifth cup should be blue and the sixth cup is empty.
If completing the experiment worksheets, now is the time to fill out the hypothesis.
Take a sheet of paper towel and fold it in half, lengthwise. Then fold it again lengthwise. Cut the ends of the paper towel so that it creates an arch over the cups, but isn't too high.
Place one half of the paper towel, lengthwise, into each cup so that one part of the paper towel is in a cup of coloured water and the other end is in an empty cup. Repeat these steps until there is one end of paper towel in each cup.
Now is the time to watch and see. The coloured will begin to crawl up the paper towel and leak into the empty cup. This dripping water will mix with other colours in the empty cups to create a rainbow.