Nuclear Fission Project

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Yes, you can do this at home.

Big Ideas: 
  • Why do nuclear chain-reactions only take place when "critical mass" is reached?
  • What affects the rate of chemical reactions?


To observe a model of how self-sustaining chemical and fission reactions work and to investigate how concentration affects the reactions.


No doubt you have heard of radioactive materials with “critical mass”, nuclear meltdowns, or gunpowder which either burns quickly or explodes in a bang. These are all flashy examples of different reaction rates.

While material properties are one factor in determining reaction rates (ie. Wood burns slowly while gasoline burns very quickly) there are many external factors that contribute to the rate of chemical and nuclear reactions.

In this experiment we will look at making a model of a reaction that will allow you to vary the parameter of concentration (for chemical reactions) and density (for nuclear reactions).


To compare different rates of reaction based on varying densities of the reactants.


  • 50 mouse traps
  • 50 ping pong balls
  • A large container to contain the reaction with a lid (clear, so that the reaction can be seen as it progresses)
  • Video camera (or a still camera capable of taking video, high speed if possible)

Key Concepts:

  • Reaction Rates


  • Data collection and experimental design.
  • Graphical analysis and curve fitting.


  1. Prime as many mouse traps you will use in your reaction
  2. Place them evenly spaced within the container
  3. Place one ping pong ball on each mousetrap
  4. Drop a ping pong ball on one of the mouse traps in the container and film the reaction happening
  5. Plot, as a function of time, the number of mouse traps that have gone off by watching the video in slow motion
  6. Repeat steps 1-5 for various numbers of mouse traps and see how they compare to each other

WARNING: Mouse traps are prone to snapping shut on unwary fingers. Be careful when setting up this experiment.

Questions to Think About:

  • Does this model better portray a chemical or nuclear reaction?
  • What other things could this reaction model?
  • What other factors affect the reaction rate that are both portrayed and not portrayed by this model?
  •  What other models can you think of that might display other factors affecting the reaction rates?
  • Is there a mathematical relation between the number of mouse traps and the way the reaction progresses?

Suggested assigned time: 

  • 1 week




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