I always end my fourth grade labs with the popular Diet Coke and Mentos experiment. The results are explosive! We used five, then six and finally seven Mentos. You could change up this investigation by using warm and cold sodas, different types or brands of soda, or sodas with the tops left off for varying amounts of time.
What would happen to your stomach if you washed down a Mentos with a glass of coke?
I sure will miss these scientists next year when they move to middle school! I hope they visit me often.