Glow in the Dark Mentos and Tonic Water Fountain

This easy science project works just like the usual Mentos™ and soda fountain except you use tonic water as the soda and you shine a black light (ultraviolet lamp) on the fountain to make it glow. Here's what you do:

Glowing Mentos Fountain Materials

• roll of Mentos candies
• bottle of tonic water or diet tonic water
• black light

It doesn't matter whether you use regular tonic water or diet tonic water. What is important is that the tonic water lists quinine as an ingredient, since this is the chemical that makes the liquid glow when it is exposed to ultraviolet light. Diet tonic water produces a fountain that is less sticky than the spray from regular tonic water. The size of the bottle isn't critical. The project works with 20-oz bottles, 1-liter, and 2-liter bottles. I have had the best luck with the 1-liter size.