Let's Go Ice Fishing

In this activity, learners are challenged to lift a floating ice cube out of a glass of water using just one end of a piece of string. Although it appears impossible at first, learners will discover that adding salt will help melt and then refreeze the string to the ice cube. Use this activity to demonstrate how salt affects water's freezing temperature as well as phase changes. This activity would work well during the winter to explain why people put salt on the sidewalks to melt ice. [Activity is publicly available through a web crawler capture on Archive.org.]