Hot Ice Tower
Liquid freezes/crystallizes into a warm tower instantly.
Teaching & key ideas
What you do: Pour solution onto seed crystal.
What students see: Liquid freezes/crystallizes into a warm tower instantly.
Why it works: Supersaturated solution rapidly crystallizes when nucleated and releases heat.
Question to ask: Why does touching one crystal change the whole liquid?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why does touching one crystal change the whole liquid?