container to do this in
First pour the baking soda into the ornament, then slowly pour the vinegar in and watch it erupt!
You could add few drops of food coloring to the baking soda if you wanted.
Why does baking soda and vinegar react to each other?
Baking soda and vinegar react with one another because they both have a lot of energy that they don't want and they can help each other get rid of it! You might think this explanation is too simple, but it's true to what's happening.
read more about why here~ http://scienceline.ucsb.edu/getkey.php?key=4147