======Liquid Nitrogen Banana Hammer======


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**Alternative titles:** Cryogenic Banana Hammer
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====Summary====                   
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====Procedure====  
  - Put on safety glasses and cryogenic gloves.  
  - Place a banana into a container of liquid nitrogen and allow it to freeze solid.  
  - Using tongs, remove the frozen banana from the liquid nitrogen.  
  - Hold the banana firmly and attempt to hammer a nail into a piece of soft wood.  
  - Observe that the banana is hard enough to act like a hammer.  




====Links==== 
The banana hammer experiment - BOC South Pacific: 
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====Variations====
  * Try freezing other fruits or vegetables (carrots, cucumbers, or apples) and test their hardness.  
  * Compare how a fresh banana bends versus how a frozen banana shatters when struck.




====Safety Precautions====
  * Safety glasses required.  
  * Wear cryogenic gloves when handling liquid nitrogen and the frozen banana.  
  * Use tongs to place and remove the banana from liquid nitrogen.  
  * Do not eat the banana (ingesting liquid nitrogen can be fatal).  
  * Only hammer into soft wood to prevent splinters or shattering of the banana.  
  * Ensure demonstration area is dry and non-slippery, as nitrogen fog can create condensation.  





====Questions to Consider====
  * Why does a banana, normally soft, become hard enough to hammer a nail?  
  * How does liquid nitrogen change the physical properties of organic materials?  
  * What happens at the molecular level when water inside the banana freezes so quickly?  
  * Why does the frozen banana shatter more easily compared to a fresh one?  
  * How could this principle be applied in real-world material testing or engineering?