Fall Leaf Chromatography Experiment
The leaves are about to change and your looking for a new NGSS experiment. A great way to explain why the leaves change in the fall is using a science experiment.
What is Chromatography? Chromatography is a method for analyzing mixtures by separating them into the chemicals from which they are made.
Grade(s): K-6 Standard connections: Next Generation Science Standards: Science and Engineering Practices Asking Questions and Defining Problems Ask questions about what would happen if a variable is changed. Planning and Carrying Out Investigations Plan and conduct an investigation collaboratively to produce data to serve as the basis for evidence to answer a question.
Objective: Separate the pigments in different colored leaves. Activity overview and background: In this activity students will explore the different kinds of pigments in leaves, how the pigments in various leaves differ, and raise questions about how colors are created. Estimated cost for activity supplies: $16.75 This activity requires the presence of a facilitator to assist students with the solvent.
Materials ! Leaves of different colors (e.g., red chard, spinach, amaranth); ($4) ! White coffee filters, cut into ½ inch wide strips ($1.50/100 ct pack) ! Clear plastic drink cups ($4/50 ct pack) ! Plastic lids with x-cut for straws ($3.75/100 ct pack) ! Solvent: white vinegar or isopropyl alcohol ($3.50/1 gal. white vinegar)
- Cut the coffee filters into strips approximately ½ inch wide and a little longer than the cup provided
- Place all materials on the table
- Pour ½ inch of solvent into a cup
- Using the edge of a penny, press a line of pigment from a leaf onto the filter strip, 1 inch from the end
- Place the strip in the cup so that the lower end of the strip is in the solvent and the line of leaf pigment is just above its surface
- Watch as the solvent moves up the paper and record your observations about the location and colors of the pigments
- Repeat with different and compare your observations
- How many different plant pigments you observe? Is there a pigment all the leaves have in common?