Fluorescent Tornado

Key Takeaways

  • Fluorescein is a dark red solid but when dropped in water, the solution takes on a bright, vibrant green color. 
  • By using a magnetic stirrer, a strong downward force is applied to the dye. This inhibits the dye from spreading, creating a tornado-like look

How to create a fluorescent Tornado

  1. Dissolve some of the fluorescein powder in a minimal amount of water. The solution should be dark red in color.
  2. Fill the graduated cylinder with water and drop in a stir bar. Then place it on the magnetic stirrer.
  3. When ready, turn on the UV-lamp, turn on the magnetic stirrer to full power, and drop in some of the fluorescein solution. 

How does Fluorescence work?

Flu­o­res­cence is the emis­sion of ra­di­a­tion (light) from a sub­stance, the atoms of which have re­ceived an ex­cess amount of en­er­gy, for ex­am­ple from ul­tra­vi­o­let light.

With­out a source of en­er­gy, the flu­o­res­cence stops. Many sub­stances pos­sess this prop­er­ty, for ex­am­ple, flu­o­res­cein, qui­nine, the chloro­phyll of plants and many oth­ers. The Stokes shift illustrates why we can’t see UV-light (which is absorbed by the substance at a lower wavelength than we can see) but can see the strong fluorescence in the visible light spectrum (in our case vibrant green).

By using a magnetic stirrer we are creating are strong downward pull. This inhibits the fluorescein from spreading, leaving some of the water uncolored. 

Experiment Video