Additional Activities Part I . My Own Air Pump Balloon Construct an air pump balloon as a device to demonstrate the application of Boyle's law. Materials: 1.5L softdrink plastic bottle, electrical tape, cutter, 2 balloons, soldering iron or heated nail 1. Make a rectangular hole in the cap of the plastic bottle with the use of cutter. 2. Cut a part from one balloon with a size enough to cover the hole 3. Tape the clut part of the balloon to cover the hole of the plastic bottle cap. Do not tape one side of the cap. 4. Using heated nail or soldering iron, poke a hole in the center part of the bottle. 5. Cover the bottle with its cap and put a balloon at the top of it. 6. Inflate the balloon by applying pressure in the plastic bottle through pumping.