Tea Rockets Explanation
First, we place a tea bag tube standing up on tin foil. The foil won't burn because of the aluminum inside. When we light the tea bag on fire the flames burn down because the fire is looking for the easiest molecule (Fuel) to burn.
The air in the top of the teabag gets hotter, making the air less dense. The tea bag is almost fully engulfed in flames. The fire reaches near the bottom. Suddenly there is enough cold air and hot air to create a vacuum, flinging the tea bag into the air above.
