Supercooled Water Freezes Instantly
Liquid rapidly turns to slushy ice.
Teaching & key ideas
What you do: Tap bottle or pour onto ice.
What students see: Liquid rapidly turns to slushy ice.
Why it works: Water below freezing can remain liquid until a nucleation site starts crystal growth.
Question to ask: Why didn't it freeze in the freezer already?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why didn't it freeze in the freezer already?