Let’s go ice fishing! It doesn’t seem possible to pick up ice with only an untied string, but it is. As long as you have the special ingredient!
This quick 3-minute science experiment uses only a handful of kitchen items and helps kids explore the freezing temperatures of freshwater versus saltwater. A supply list, printable instructions, and a demonstration video are included to make planning easy.
How to Pick Up Ice with String Video
- Empty Glass or Bowl
- 5-6 Pieces of Ice
- 1/2 Cup Water
- Piece of String
- 1/2 Teaspoon Salt
Step 1 – Put 5-6 pieces of ice into an empty glass or bowl.
Step 2 – Next, add the water into the glass.
Step 3 – Try to use the string to pick up a piece of ice. You will find that it isn’t possible.
Step 4 – Next, lay the piece of string over the ice.
Step 5 – Sprinkle the salt over the string and wait for a minute.
Step 6 – After a minute has passed, pick up the string and watch what happens.
How Does the Experiment Work?
When salt comes in contact with ice, it causes the ice to melt a little. The small amount of water from the melted ice and the salt combine together, lowering the freezing point of water. Saltwater has a lower freezing point than fresh water by about 4℉. This lowered freezing point makes it harder for water molecules to recrystallize into ice.
In this experiment, once the salt was added to the ice, the ice melted a little and then quickly refroze around the string. This causes the ice to stick to the string when it is pulled out of the glass.
The same concept is used when you add salt to your driveway or sidewalk during the winter. The salt lowers the freezing point of water, causing it to melt so you can more easily remove it.
I hope you enjoyed the experiment. Here are some printable instructions: