Classroom mode
Run it in class
Why does soap wash off greasy hands but water alone just rolls off the grease?
Show of hands — before you project anything
Before we test it: which will rinse cleaner, a hand washed with plain water or one washed with soap? Why?
- 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
- Before we test it: which will rinse cleaner, a hand washed with plain water or one washed with soap? Why?
- Predict what happens to a grease drop when many soap tails dig into it at once. Then watch the explainer break it into tiny balls.
- Soap doesn't destroy grease, it just wraps it so water can carry it off. Predict why you still need running water even after using soap.
Where it shows up in real life
- Washing greasy hands after eating pizza or fries
- Dish soap cutting through a greasy pan after dinner
- Shampoo lifting oil off your hair in the shower
A prediction-first worksheet — no answer key.
zero prep · no login · any projector
Winding down at home? Family mode ·
Explore every question
Why does soap wash off greasy hands but water alone just rolls off the grease?
Predict — what do you think will happen, and why?
Talk about it
- Before we test it: which will rinse cleaner, a hand washed with plain water or one washed with soap? Why?
- Predict what happens to a grease drop when many soap tails dig into it at once. Then watch the explainer break it into tiny balls.
- Soap doesn't destroy grease, it just wraps it so water can carry it off. Predict why you still need running water even after using soap.