How to Make a Color Separator

Science fairs are often one of the reasons why parents pull their hair out, particularly when children wait until the last minute to tell their parents about their project deadline. The following project is easy to make and quick to throw together letting them put together a project that's sure to please their science teacher even if they have procrastinated.

This simple project requires only a jar, water, strips of paper towels and markers in varying non-primary colors. It is meant to be demonstrated either in class or at a science fair so your child should practice the demonstration at home first. Most of the little preparation required can be done at home.

While simple this project demonstrates two concepts. The first is the concept that all colors are in fact mixtures of the primary colors red, yellow and blue. The project also demonstrates the complex concept of capillary attraction. This concept may even help your child win the science fair with a project that takes about 15 minutes to assemble.

Begin the project by obtaining a glass jar and filling it 4/5ths of the way full with water. The size of the jar isn't important so long as it can hold at least a cup of water, anything smaller will be difficult for your child's classmates to see.

After you have prepared the jar cut paper towels into strips. The strips should be long enough to place over the rim of the jar with one end of the strip dangling inside the jar and dipped into the water about 1 inch. If the strips are long enough their other ends should hang over the rim to the outside of the jar and dangle down 2 to 3 inches. The total length required will depend on the size of the jar and how much water you put in it. I recommend that you test out several lengths of strips until you find the right one.

After you have cut four to five strips of paper towel use a different colored marker to put a circle on one end of each strip. You will need to use non-primary shades such as orange, green, etc. in order to see them separate into their primary colors.

Once you have put a circle on the end of each strip, drape each strip over the rim of the jar. Keep the end of the strip with the colored circle outside the jar and dip the other end of the strip into the water inside the jar. Leave the strips hanging on the rim of the jar. It will take roughly 15 to 20 minutes for the capillary action, which is a fancy name for the force that makes the paper absorb the water over the side of the jar, to reach the colored circle and cause the color to separate. Once this happens the shades you have chosen will be separated into their primary color components.

If your child does the demonstration once at home he or she will know the length of the strips they need and how much water they should put in the jar. They can then cut appropriately sized strips the evening before and color a circle on the end of each one. They can also fill a water bottle with the exact amount of water they will need to put in the jar. Doing these things ahead of time will make it a snap for your child to put the project together and give their demonstration in class or at the school science fair.