Here is the original burping bottle I created. I also switched it up for Halloween. Make sure to read the whole blog. If you don't have a tornado tube that is okay. I have a solution for that too.
Heres I how I made it.
Place a straw through the hole in the tornado tube. Fill clay around the straw on both sides of the tube. It must be air tight. Make sure the straw does not get squished. Cut the top bottle so it is a funnel. Screw both bottles to the tornado tube. Stand it upright. Pour water into the top bottle. Make sure it is over the height of the straw. It might start on its own or give the bottle a little squeeze.
If you don't have a tornado tube you can use a potato. Yes, I just said potato. Cover your finger over one end of the straw. This will make it easier to poke through the potato. Use a small potato or cut a piece. Stab the straw through the potato. Remove the potato piece from inside the straw. Using your muscles screw the potato to the openings of each bottle. This is tricky, but you will get an air tight seal. Add water and use it just like the tornado tube burping bottle.
Create a Halloween Twist.
Add oil into the bottom bottle and colored water into the top. As the water enters the bottle students will see a bubbling concoction.
Don't forget to enter the Rafflecopter during the 13 Days of Halloween Event.