Veg oil, water, alka seltzer, food coloring, and a bottle. Fill a bottle 2/3 with veg oil and 1/3 with water (keeping in mind to leave 1" at the top). Add 10 drops food coloring. Add 1 alka seltzer (broken in a few pieces, adding one piece at a time - when first piece stops bubbling, add next) and watch the colors.
Alka Seltzer Rocket Eruption Science Activity
Alka Seltzer Rocket Set Up for Eruption
Alka Seltzer Heartburn Relief Strawberry and Orange Chewable - 6ct