Learners compare the properties and solubilities of Styrofoam (TM), ecofoam packing peanuts, and popcorn. First, the solubility of each substance is tested in water. A drop of iodine is added to each solution and a color change indicates the presence of starch. Only the biodegradable substances dissolve in water, and the iodine test indicates these substances were made from starch. Acetone is needed to "dissolve" the Styrofoam, and even with a drop of acetone, it does not dissolve completely. For safety reasons, this activity works best as a demonstration for younger audiences.