======Freezing a Bouncy Ball in Liquid Nitrogen======


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**Alternative titles:** Unbouncy Ball Experiment
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====Summary====                   
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====Procedure====  
  - Place a bouncy ball into a container of liquid nitrogen using tongs.  
  - Leave the ball submerged for several minutes until thoroughly cooled.  
  - Wearing safety glasses and gloves, remove the frozen ball.  
  - Drop the ball onto a hard surface and observe its reduced bounce (or shattering).  
  - Allow the ball to return to room temperature and test again to see its bounciness restored.  




====Links==== 
Can you FREEZE a bouncy ball? | liquid nitrogen experiment - Wonderlab+: 
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Don't Put Bouncy Ball in Liquid Nitrogen - Mr. Ax: The BackBencher Experiment: 
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====Variations====
  * Compare different types of balls (rubber superballs, tennis balls, racquetballs).  
  * Drop the frozen ball from different heights to see if it shatters or simply thuds.  
  * Test the bounce height of the ball at room temperature versus after freezing.  
  * Use slow-motion video to capture the difference in impact behavior.  




====Safety Precautions====
  * Safety glasses required.  
  * Wear cryogenic gloves when handling liquid nitrogen and the frozen ball.  
  * Handle the ball with tongs immediately after freezing — it may be brittle and sharp if it breaks.  
  * Only perform in a well-ventilated area to prevent nitrogen buildup.  
  * Do not attempt this with balls containing liquids or pressurized gas (they may burst).  





====Questions to Consider====
  * Why does rubber normally allow a ball to bounce?  
  * How does liquid nitrogen change the molecular structure of rubber?  
  * Why does the frozen ball sometimes shatter like glass?  
  * What type of energy conversion allows a normal ball to bounce?  
  * How does warming the ball restore its elasticity?  
  * What other everyday materials might behave similarly when frozen with liquid nitrogen?