Baking soda, vinegar and food coloring

West liked to hold baking soda while I poured on vinegar so he could feel the fizz

Such a simple, fun activity! You probably have all the ingredients on hand, if not, they're cheap. We poured the baking soda into a drawer organizing tray that we had, added a few drops of food coloring to the baking soda and took turns pouring the vinegar on. The bubbles would fizz up in bright colors and mix with each other. Each time we added more vinegar, because there was still a lot of baking soda on the bottom, new colors were created.