Summary
Mark dumps 25 million water-filled Orbeez beads into a pool and tests whether a person sinks or floats in them. It's a playful look at density and buoyancy.
Viewer safety
Ages 7+
Made for a general YouTube audience — an occasional mild or bleeped word can slip in, so preview if your classroom bar is strict.
Our rating is a quick teacher-to-teacher guide — preview before showing.
Teaching resources
Discussion questions
Talk about it
Whether something floats depends on how its density compares to what's around it. Orbeez are mostly water, so they behave in surprising ways.
- What does it mean for something to float rather than sink?
- Why might a person sink into Orbeez but float on top of some other materials?
- How could you test whether one Orbeez ball floats in plain water?
Quick work-a-long
Vocabulary: density, buoyancy, sink, float.
Try it: Drop a grape and a piece of cork into a cup of water. Predict which floats, then test. Explain using the word density.