Classroom mode

Run it in class

Why does ice float?

Show of hands — before you project anything

Predict which of two equal-size cups is heavier, one of water and one of ice, then explain your reasoning before weighing.

  • A Way more than you'd guess
  • B About what you'd guess
  • C Way less than you'd guess

Count the votes out loud. Hold them to it — then watch.

Project it (fullscreen)

Discussion prompts

  • Predict which of two equal-size cups is heavier, one of water and one of ice, then explain your reasoning before weighing.
  • Freezing adds no molecules and removes none, so how can a cup of ice weigh less than a cup of water?
  • Predict what would happen to fish in a pond if ice were heavier than water and sank to the bottom each winter.

Where it shows up in real life

  • An ice cube bobbing in a glass of juice or soda
  • A frozen lid on a winter pond with fish still alive underneath
  • An iceberg showing only its tip while nine-tenths hides below the waterline

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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