Cat's Science club

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The Science

The mentos has tiny indents all over its surface. These are called nucleation sites. Carbon dioxide from the soda build up in these spots, forming bubbles.  The mentos sinks and the the bubbles rise.  What is in the way of the bubbles?  Liquid.  The bubbles rising to the top force the liquid out the bottle in an awesome eruption!  Now would this be a chemical reaction?  Why or why not?


and Soda


  • 2 liter of diet soda.

          -Any soda will work but diet doesn't leave a sticky mess behind.

  • Mentos
  • Safety goggles
  • Geyser tube (optional*)

          -Sold at stores or at


  1. Find a flat surface
  2. Put on safety glasses to protect eyes
  3. Open diet soda and place on flat surface.
  4. Open up mentos container
  5. Insert mentos into bottle
  6. Move away quickly

*Optional geyser tube is recommended but not needed.  The tube allows for a high spray of the soda in a narrow flow.  Also you have less of a chance to get drenched with the soda!  If you use the tube, please follow directions on the packaging.