Salt Lifts an Ice Cube on String
String freezes onto the ice.
Teaching & key ideas
What you do: Lay string on ice, sprinkle salt, wait, then lift.
What students see: String freezes onto the ice.
Why it works: Salt melts a thin layer; surrounding cold water can refreeze around the string.
Question to ask: Why did salt help the string stick?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why did salt help the string stick?