The white layer inside the orange peel contains few soluble substances and a lot of air, which is why it floats on water.
Materials Needed
- A glass of water
- An orange
- A knife
Instructions
- Pour water into the glass.
- Drop the orange into the glass.
- The orange does not sink!
- Peel the orange.
- Drop the peeled orange into the water.
- The orange sinks to the bottom!
Explanation
The main factor in the buoyancy of citrus fruits is the structure of the peel.
The white layer inside the peel contains few soluble substances and a lot of air. In contrast, the flesh of the fruit contains a high amount of sugar and acid, but very little air.
An orange without its peel is denser, has more mass, and therefore sinks quickly in water.
Mass is the amount of matter in an object. The average density of an object is the ratio of its mass to its volume.
The experiment shows that the buoyancy of an orange is determined by the thickness of the white layer beneath the peel. The thicker the white layer, the more air it contains, and the higher it floats.
