Classroom mode

Run it in class

Why does red cabbage juice turn pink in lemon and green in soap?

Show of hands — before you project anything

Why can a color change be evidence about an otherwise clear liquid?

  • 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 can a color change be evidence about an otherwise clear liquid?
  • What does the unchanged purple control cup add to the experiment?
  • Why is cabbage indicator useful for broad comparisons but weaker than calibrated pH paper for an exact measurement?

Where it shows up in real life

  • pH test strips used for swimming pools and aquariums
  • universal indicator solution in a science classroom
  • plant pigments whose appearance depends on their chemical surroundings

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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