Marshmallow in a Syringe

1. Marshmallow in a Syringe Materials: Large needle-free syringe; mini marshmallow What you do: Seal syringe tip; pull and push plunger. What students see: Marshmallow grows and shrinks. Question: Is the marshmallow making more air? 2. Self-Starting Siphon Materials: Two cups at different heights; flexible tubing; water What you do: Prime tube, then place outlet lower than source. What students see: Water keeps flowing uphill over the rim then down. Question: Why can water travel up before it travels down? 3. Heron's Fountain Materials: Prepared 3-bottle Heron's fountain What you do: Pour water into top basin to start fountain. What students see: Water jets upward with no pump. Question: What invisible thing is pushing the fountain water?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Is the marshmallow making more air? Question: Why can water travel up before it travels down? Question: What invisible thing is pushing the fountain water?