Ice Cube on a String

This simple experiment demonstrates how salt lowers the freezing point of water. By sprinkling salt on an ice cube and laying a string across it, the ice melts slightly and then refreezes, trapping the string so the ice cube can be lifted.

1. Fill a glass to the top with water.
2. Place an ice cube into the glass.
3. Cut a piece of string longer than the width of the glass.
4. Lay the string across the top of the ice cube.
5. Sprinkle about half a teaspoon of salt onto the ice cube.
6. Wait about 30 seconds.
7. Gently lift the string. The ice cube should rise with it.

How To Pick Up Ice with a String Experiment - Cool Science Experiments Headquarters:

Pick up Ice with a String Experiment | How does it work? - Hungry SciANNtist:

📄 Ice Cube on a String Experiment - Little Passports: https://www.littlepassports.com/blog/science/ice-cube-string-experiment/?srsltid=AfmBOoqOhxRR_R-WCP8QhIEvfJ5vB_pen27pg-mlgsGFNcYrveajiPLD

• Try different amounts of salt to see how quickly the ice cube attaches to the string.

• Safe for children with supervision—no hazards beyond handling ice.
• Avoid spilling water to prevent slipping.
• Dispose of melted ice water safely.

• Why does salt make the string stick to the ice cube? (Salt lowers the freezing point, melting a thin layer of ice, which then refreezes around the string.)
• Why is salt spread on roads in winter? (To prevent ice from forming and make roads safer by lowering the freezing point of water.)
• What would happen if you tried this with sugar instead of salt? (Sugar does not lower the freezing point enough, so the string will not stick.)
• How is this experiment an example of a freezing point depression? (Salt ions disrupt the structure of ice, requiring a colder temperature to stay frozen.)