Directions: Gather the following items:
Place cornstarch inside two pieces of plastic wrap. Secure the plastic-wrapped bags at the top with twist ties. Make sure the cornstarch does not leak out. Use a needle to make several holes in one of the bags. Place each bag of cornstarch into a glass beaker filled with water. Be sure the top of the bags stays out of the water to prevent leakage into the beaker. Put several drops of iodine into the water of each beaker.