DemoTK

Ice Fishing with Salt and String

String picks up the ice cube.

Teaching & key ideas

What you do: Lay wet string on ice, sprinkle salt, wait ~30 sec, lift. What students see: String picks up the ice cube. Why it works: Salt melts a thin layer; diluted water can refreeze around the string. Question to ask: How did the string get 'stuck' to ice?

Lesson flow

Predict → demonstrate → observe → briefly explain → ask: How did the string get 'stuck' to ice?