Education, fun and safety for kids online
Education, fun, games and safety for kids online

The Levitating Ice Cubes Experiment

The Levitating Ice Cubes Experiment

Use this magical science experiment to impress your friends as you make ice cubes dangle from a piece of string! Such a feat is sure to conjure up some serious questions about science, salt, and magic from your audience!  Don’t worry though, we’ll explain the reaction in the cup so you can handle the inquisitive, wide-eyed reactions of your friends.

Materials for the experiment:

  • Clear cup
  • Ice cube
  • Salt
  • Food coloring (optional)
  • String

Experiment:

  1. Fill the cup ¾’s full of water.
  2. Put a drop or so of food coloring into the salt to create magical, colored salt crystals. (We used green; with the addition of food coloring, the attachment of ice to the string will become more apparent.
  3. Now, place the ice cube into the water.
  4. Pace the string inside the water and over the ice cube. Put on display the fact that the string does not stick to the ice cube.
  5. Once that idea is obvious to your child, sprinkle the colored salt onto the ice cube.
  6. Quickly place the string onto the ice cube and let it sit for about 2 minutes.
  7. Pull the string out of the water and show your child that the ice cube is now securely attached to the string, like magic!

Ooooh!

The science behind the experiment:
Salt lowers the freezing point of the water.  Therefore, when the salt hits the ice cube, the ice cube begins to melt a little bit. After this reaction has occurred, the salt begins to weaken and becomes captured by the ice, freezing the thread to the ice cube.

Where do we see this reaction in our everyday lives?
Ever wonder why oceans never freeze? Since the salt compound found so heavily in the ocean controls the ocean’s freezing point, salt lowers water’s ability to solidify. Even when the temperature is zero degrees, oceans are still filled with salty water!

Also, have you ever wondered why people salt icy roads? This experiment must have made that a little clearer! We’ve shown that salt has the ability to melt ice. This is especially helpful in cold, snowy places where people walk or drive everyday, to keep paths and roads slip-free!