Jell-O gelatin comes in powder or solid form, and is typically used to create desserts, such as fruit molds, no-bake pies, flavored punch and whipped parfaits. The powder form can also be used to create glow-in-the-dark science projects that use additional elements, such as quinine in tonic water or phosphors in petroleum jelly, which are best revealed when placed under a black light.
The standard method of making Jell-O from its powder state involves heating tap water, mixing it with the powder, stirring in a cup of cold water and pouring the liquid into a glass pan, mold or bowl. By substituting tonic water for the tap water, you introduce the element of quinine, which enables the Jell-O to show up in the dark under a black light.
Jell-O powder can be used to make punch after it's mixed with boiled water and flavored with a large can of juice. One way to create a glow under the black light is to use tonic water instead of tap water. However, the quinine in the tonic water will add a bitter flavor to the punch. Experiment with different sweeteners, such as lemon concentrate, sugar or soda, to eliminate the bitter taste.
Petroleum jelly contains phosphors that absorb radiation and emit it as visible light. If you dip your hand into it and then into Jell-O powder, you can create hand prints on paper or another solid object that shows up under a black light. The random granules of the Jell-O will create patterns that reflect the light back in a different intensity than the petroleum jelly.
Measuring Quantam Yield
The experiments already mentioned will result in a bright blue glow that has a measurable optical effect. Quinine and phosphors emit photons that create a fluorescent quantum yield, which is the measurement of how efficiently absorbed light creates a glow under an ultraviolet light. Experimenting with the amount of tonic water or petroleum jelly will change the intensity of the emissions, and can be mathematically measured by determining the number of photons emitted to the number of photons absorbed.