Ice Magic. Fun with Grandchildren.

Ice cubes in a tray

Ice cubes in a tray (Photo credit: Wikipedia)

Can you pick up an ice cube with a piece of string?


  • Glass of water
  • Ice cube
  • Piece of string
  • Salt


  • Fill the glass with water
  • Drop an ice cube in the water
  • Lay a string across the ice cube
  • Try to pick up the ice cube by lifting the ends of the string.

What Happens?

The ice cube stays in the water.

What Is the Trick?

  • Lay the string across the ice cube
  • Sprinkle salt from a salt shaker over the string onto the ice cube
  • Count to 30.
  • Pick up the ends of the string. The ice cube will pick up, attached to the string.

What Happened?

The ice melts around the string where the salt hits it. Then, the water remelts around the string, so you can pick it up.

If you had added salt to the water, instead of the ice, the ice cube would have melted slower, but you wouldn’t have seen the dramatic effect of the string sticking to the ice cube.

As it was, the temperature of the water layer on top of the ice cube was lowered with the salt, enough to melt the ice around the string. However, it quickly refroze and trapped the string in the refrozen ice.

The ice underneath the string did not touch the salt, so it did not melt.

Only the ice around the sides of the string melted.

Fresh water from the melted ice cube then flowed over the string and refroze.

Click here to watch a video of this experiment at

What Else Can We Do with Salt and Ice?

Communities that want to clear their roads of ice in the winter often spread salt on the roads, or now, salt water. The salt mixes with the melted snow on the roads and keeps them from icing over.

Homeowners often sprinkle salt on their front steps in the winter to keep the ice from freezing.

This only works down to a certain temperature. If the temperature is below 10 or 15 degrees Fahrenheit, it no longer works.

Then, spreading sand is more helpful than salt.

Using salt to lower the temperature of water used to be the way people made ice cream. Today, you can get the same effect with a Ziplock bag, salt and ice and make ice cream in ten minutes.

Thanks to for this activity. 

Have your grandchildren ever asked why we spread salt on the roads in the winter?

Do you live somewhere where it is too cold to use salt for the roads?

Have you noticed the snail trails of salt water on the roads when your area is expecting snow?

To you and sharing what you know with your grandchildren.


Carol Covin, Granny-Guru

Author, “Who Gets to Name Grandma? The Wisdom of Mothers and Grandmothers

Click here to order this blog on your Kindle.


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