Lesson Plan Title : Colors of the Rainbow

Age Range: Kindergarten through grade 2 (Primary)

Overview and Purpose: Students use water and food coloring to create a Saint Patrick's Day rainbow. They make the colors by conducting an experiment that allows them to study the process of dispersion.

Objective: The student will be able to see how the process of dispersion works.


Plastic peanut butter jars with the labels removed

Food coloring


Ask your students to name the colors of the rainbow. Label the lid of each jar with each one of the colors. Ask the students what they think will happen if you drop some red food coloring into one of the jars. They will probably say the water will turn red but have them think more critically. How fast will it turn red? What shade of red will it be? Then put two drops of red food coloring in the jar. Have them observe what happens next. Ask them how that compares with their predictions.

Divide the class into small groups and have each group conduct the experiment with a different color so they will have all the colors of the rainbow. Some groups may have to add two primary colors together to get the secondary color. Have them shake the jar after they add the first color and observe what happens. Then have them add the second color. When all the groups have finished, have them put the lids on their jars and line that them up to make a rainbow. Discuss as a class any questions the students have about the experiment.

Wrap Up:

For homework, have students draw a picture about what they saw happen in their experiment. More advanced students, can be asked to write a short paragraph explaining the dispersion process.