Classroom mode

Run it in class

If you dissolve a whole sugar cube in water, what will a balance do while the cube disappears from sight?

Show of hands — before you project anything

Why record the beam before stirring instead of relying on memory?

  • 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

  • Why record the beam before stirring instead of relying on memory?
  • Which variable changes in the hidden experiment, and which conditions stay matched?
  • After watching, explain how the molecular picture accounts for both the clear-looking cup and the measured result.

Where it shows up in real life

  • Stirring sugar into a breakfast drink until no cube is visible
  • Salt mixing into pasta water
  • Crystals appearing after a drop of salty water dries

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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