demonstrations:sinking_orange_floating_peel
Sinking Orange Floating Peel
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Density and Buoyancy
Alternative titles: Natural Life Jackets
Summary
Two oranges are placed in water—one with the peel and one without. Surprisingly, the heavier orange with its peel floats while the lighter, peeled orange sinks. The porous peel traps air, reducing the orange’s density and allowing it to float.
Procedure
- Fill two large glasses or containers with water.
- Place an unpeeled orange into the first container and observe that it floats.
- Peel the second orange and place it into the second container of water.
- Observe that the peeled orange sinks to the bottom.
- Compare the results and discuss why the heavier orange floats.
Links
Sinking Orange Floating Peel - 4SciFun:
📄 Why Does the Heavier Orange Float Science Experiment - Cool Science Experiments Headquarters: https://coolscienceexperimentshq.com/why-does-the-heavier-orange-float/
Variations
- Try the experiment with other fruits that have porous skins (e.g., lemons, limes, or grapefruits).
- Test if partial peeling of the orange changes whether it floats or sinks.
- Weigh the oranges before the experiment to emphasize that the floating orange is actually heavier.
Safety Precautions
- Handle the glass containers carefully to avoid spills or breakage.
- Clean up any spilled water to prevent slipping.
- Use caution when peeling the orange to avoid cutting yourself.
Questions to Consider
- Why does the unpeeled (heavier) orange float while the peeled (lighter) one sinks?
- What role does the peel play in helping the orange float?
- How does this experiment relate to the concept of density and buoyancy?
- Can you think of other real-world examples where trapped air helps objects float (e.g., life jackets, boats)?