Test to see what pigments are present in various plant leaves. Place a small amount of salt water into a 250 ml beaker. Place the leaf on some chromatography paper and rub it with the edge of a quarter to transfer some of the pigment to the paper. Staple the two ends of the chromatography paper together to create a circle, with the pigments facing outward, and place it into the salt water. The salt water causes the water to rise up through the paper and separates the pigments from one another.
Not all plants have green leaves. Some plants have red or purplish leaves. Gather plants that have various shades of greens, reds and purple. Repeat the chromatography experiment using the salt water as a solvent. Besides blue and yellow, which are present in various amounts for all green leaves, find what other pigments are present. Look for patterns in the experiment. For example, if another leaf was given to you to test, can you predict what pigments will show up before completing the experiment?
Many plants begin to change color in the autumn. While this change is occurring some leaves on the trees still are green while others have changed completely. Complete chromatography experiments on each color of leaf present on the plant. Look to see if the pigments present in each leaf are the same or if the pigments are different. If they are different, explain why the pigments have changed within the leaf.
Salt water is not the only solvent you can use to test the pigments in plant leaves. You can also use acetone and ethyl alcohol. Test to see which of the three solvent types works best at separating the pigments in plant leaves. Prepare three separate 250 ml beakers with each of the solvents and place chromatography paper with a pigment sample taken from the same leaf into the beaker. See if one solvent separates out the pigments more clearly than another.