Glow in the Dark Jell-O

If you’ve ever wanted those glow in the dark stickers, you will love this activity! Kids will be able to learn about ultra violet light and florescence by making glow in the dark Jell-O!


  • Jell-O
  • Tonic water
  • A clear glass bowl or clear cups
  • A black light


  1. Microwave 1 cup of tonic water for 45 seconds or until boiling.
  2. Stir the boiling tonic water into the Jell-O mix until it is completely dissolved.
  3. Stir in 1 cup of cold tonic water
  4. Refrigerate your Jell-O for four hours or until firm
  5. Place your Jell-O in a dark room and shine your black light on it.


You can think of light as a wave and as it propagates, it also vibrates. Light from a light bulb, flashlight, or even the sun vibrates in all directions as it propagates. A polarizer only allows light that is vibrating in a certain direction pass through.
Light that reflects off of a horizontal surface vibrates in the horizontal direction (polarized horizontally). So if the polarizer is oriented vertically, it will block that reflection. This is how polarized sunglasses block glare. Now take a look around and see if you can other sources of polarized light.