Packing Peanuts Mini-Lesson Vanderbilt Student Volunteers for Science Spring 2005 Training Presentation

Important!!! Please use this resource to reinforce your understanding of the lesson! Make sure you have read and understand the entire lesson prior to picking up the kit! We recommend that you work through the kit with your team prior to going into the classroom. This presentation does not contain the entire lesson—only selected experiments that may be difficult to visualize and/or understand.

I. Introduction (pg. 1) Define biodegradable for the students: Something that breaks up or decomposes after being exposed to the environment. Explain to the students that one of the packing peanuts is biodegradable and one isn't. The one that is biodegradable is made out of natural starch and their job is to figure out which one is starch.

II. Experiment (pg. 2) Tell them to place the 1 oz cup in the aluminum pan. Each VSVS team member should take one of the iodine bottles and be ready to add two drops of iodine solution to the 1 oz cups of cornstarch. Have students remove the lid from the 1 oz cup of cornstarch and go around to each pair and add two drops of iodine solution to their 1 oz cup of cornstarch. Ask them to write down what happens on their observation sheet. –The starch in the tested area is a dark purple/black. –Explain that this is a positive test for starch.

II. Experiment (cont.) Give each group one #1 packing peanut and one #2 packing peanut. (Call them #1 and #2, not starch and polystyrene.) VSVS teams members should take one of the iodine bottles and add two drops of iodine to the surface of each packing peanut. Ask them to write down what happened. –The #1 packing peanut gives a positive test for starch.

II. Experiment (cont.) Put a #1 packing peanut in each of the #1 cups and a #2 packing peanut in each of the #2 cups and give each pair one of the #1 cups and one of the #2 cups, a plastic spoon, and a water bottle (shared between two pairs). Tell the students to fill the glasses half- full with water. What do they observe about the packing peanuts? –Both float on water Tell them to take the spoon and try to push down each packing peanut under water while stirring the water and observe if anything else happens. What do they observe? –The #1 (starch) peanut dissolves in about two minutes – breaks down and goes into solution while the polystyrene peanut doesn't change.

Discussion Question: Which packing peanut is biodegradable? –The #1 (starch) peanut is because it dissolves in water. See manual for explanations Clean-up: Empty the cups and the water bottles down the drain. Put used plastic cups, cornstarch containers, spoons, and used polystyrene peanuts in the trash bag. Return aluminum pans, iodine bottles and water bottles to the box. Place the trash bag in the box and bring back to VSVS lab as soon as possible.