You will need, an empty plastic water bottle, vinegar, baking soda, and a piece of printer paper. The more vinegar and baking soda you use, the bigger the explosion will be.
Step 1: Adding the Baking Soda and Vinegar
Unscrew the lid to the bottle and fill it about half way with vinegar. Take the piece of paper and put it down horizontally. One the bottom of the paper, shake baking soda on the edge. It doesn't matter how much you put on, but the more there is, the bigger. Roll the paper up so that it is a tight, skinny tube. Fold up the ends so nothing falls out. Fold the paper in half if it won't fit in the bottle. (The black line is where the baking soda should go.)
Step 2: Preparing
Once you have the materials ready, go outside into a space where the bomb won't hit anything (or anybody). Shove the piece of paper with the baking soda into the bottle and quickly screw the cap on really tight. Begin to shake it until the bottle gets hard.
Step 3: The Throwing
The bottle should be really hard and if the bottle has grooves in it, the should be smoothed out by the pressure. When you think it is ready, throw the bottle containing the vinegar and baking soda as hard as you can into the air as high as you can. Run away quickly and out of the way of everything.
Step 4: Impact
After you run away turn around and watch. When the bottle hits the ground, the bottle splits down the side and the vinegar and baking soda comes out. If you are using distilled white vinegar, the bomb will make a gunshot-like noise. (That is what I used) If you use a different kind it may turn out different. The impact only lasts a short amount of time, but if you video tape it, you can watch it in slow motion and see what really happens. The picture is of what happened to the bottle afterward.