Walking Rainbow experiment jars ()
This experiment shows TWO different scientific principles!
The capillary action of water.
This means that water will defy gravity and wick itself up the paper towel. It happens because water molecules bond to each other, which is called cohesion. It also helps that water molecules bond to the paper, which is called adhesion.
The visible spectrum and color theory.
There are three primary colors: red, blue and yellow. Each one has a special wavelength of light. You see red on a paper towel because the red dye bounces back red’s wavelength. When two primary colors are mixed, a mix of wavelengths bounces back and you see a new color. These are the secondary colors: purple, green and orange.
You will need:
6 glass jars or glasses
Red, yellow and blue food dye
Water
Paper towels
Procedure:
1. Place your jars in a small circle. They should touch each other.
2. Fill three jars with water. Leave an empty jar between each of them.
3. Put food dye in the water. Make one jar red, one jar blue and one jar yellow. It takes a lot of dye to get good colors.
4. Fold 6 paper towels into strips. Place the paper towels around the circle. One end goes in a water jar and the other end goes in an empty jar. Make sure they are folded over the edges of the jars, not high in the air.
5. Watch as the colored water wicks itself up over the paper towel and drops into the empty glasses. As it mixes, the secondary colors will appear.
Artists take note!
When the experiment is done, gently unfold the paper towels. Lay them out to dry. They make colorful craft supplies.
Secondary colors are not made with equal parts of primary colors. There is more of the lighter color than the darker one. This is good to know when mixing paint. To make green, begin with a large amount of yellow and mix in small drops of blue until it is the green you want. To make orange start with yellow and add a little red. To make purple start with red and add small bits of blue.
