Colorful Water Mixing

This is the perfect, easy experiment for any day! If you’re busy, you can quickly set up the experiment and come back an hour later to see the astonishing results. If you want an entertaining experiment, you can set up the experiment and watch in amazement as the colors mix and produce beautiful results. In any case, this is a fun, easy experiment that requires only a few, household items!

What you need:

• seven clear plastic or glass cups
• red, yellow, and blue food coloring
• two paper towels
• water
• plastic spoon

Steps:

• Place the seven cups in a row

• Fill the first, third, fifth, and seventh cups with water (the more filled the cups are, the better this experiment works)

• Put four drops of red food coloring in the first and seventh cups

• Put four drops of yellow food coloring in the third cup

• Put four drops of blue food coloring in the fifth cup

• Mix each cup to ensure the food coloring is evenly dispersed throughout the water (make sure to wipe the spoon between cups so the colors do not mix)

• Take a paper towel and cut it into four thick, short strips
• Fold each strip in half
• Place the strips in between each of the cups, forming a bridge between the cups

• Watch as the colors mix and form a rainbow (you will see some results immediately, but it may take up to an hour for the colors to fully mix)

• You can also remove a red cup and put the rest of the cups in a circle to see the color wheel

How do the colors mix?

The water moves up the paper towels through a process called capillary action. Capillary action occurs when the forces of adhesion, or the attractive forces between a water molecule and another substance, are greater than cohesion, or the attractive forces between multiple water molecules. The paper towel is made from fibers to which the water is attracted, and the water is able to travel up through the gaps in the fibers. This process is also what helps water climb from a tree’s roots to the leaves at the top of the tree. When the water travels through the paper towel, it is released on the other side of the paper towel into the empty cup. The colors mix to form new colors: red and yellow create orange, yellow and blue create green, and blue and red create purple.