Liquid Nitrogen

This demonstration is always a favorite among kids of all ages (and most adults too!).  The point of the activity, is to show how temperature can affect different types of materials and states of matter, such as gases, liquids and solids.  Materials needed:

  • Liquid Nitrogen (contact us if you need access to this)
  • Balloons (optional)
  • Fruit (optional)
  • Racquetballs (optional)
  • Flowers (optional)
  • Marshmallows (optional)

The true fun part of this demo is that is can be constantly improved with a little imagination.  Listed above are some of the common items we put into the nitrogen, but there are tons of other ideas you might be able to come up with on your own.  For the items we listed, here is a brief overview of what they are meant to teach.  You can blow a balloon up and place it in the nitrogen.  As the balloon gets cold it will shrink as the gas molecules condense.  Fruit and flowers, which are usually soft can be frozen hard and used as a hammer to secure a nail into a board (the flower can not be a hammer, but you can break the petals off on a surface and show how brittle it has become).  This is because of all the water molecules inside the fruit that freeze at such a low temperature.  Racquetballs which usually bounce become very hard and will break when you throw them at the ground.  Their polymer molecules which are usually stretchy are frozen together.  Finally, marshmallows are just fun to eat, and if you put a frozen one in your mouth the water vapor will condense and you can blow out steam, similar to a dragon.