How to Make a Volcano out of Mentos and Soda (with Pictures)
Add the Mentos. Place your funnel so it fits within the mouth of the bottle. Drop 4-5 whole Mentos into the bottle all at once. Quickly remove the funnel and back away as the bottle will soon spout off fizzy soda. If you want the explosion to occur at a slightly slower rate, then crush up the Mentos before you drop them into the bottle.