Kitchen Volcano
["1/4 c. vinegar", "1 Tbsp. baking soda", "food coloring (optional)"]
["Place an 8 to 10 ounce cup or glass on a pie plate or other tray.", "Pour vinegar into cup.", "Add food coloring, if desired.", "Pour in baking soda and stand back."]
["vinegar", "baking soda", "food coloring"]