What you’ll need
What you’ll need
- A tall, narrow glass
- A long-handled spoon
- Orange or multi-vitamin juice
- Red syrup (e.g., raspberry)
- Small marshmallow pieces
- Smarties®
- A glass of water
Variation A:
- Sparkling water
- Blue food coloring
Variation B:
- Coconut milk (from a Tetrapak container, shake well before pouring)
How to do it
How to do it
Well spotted!
Well spotted!
- The sugar syrup mixes only a little with the fruit juice and most of it sinks to the bottom of the glass where it forms a colored layer.
- If poured carefully, the colored mineral water or the coconut milk should form a layer on the surface of the fruit juice.
- Smarties® won’t float on the surface of the drink, but if you use a piece of marshmallow as a “boat” you can place two Smarties® on top and it won’t sink.
What's the secret?
What's the secret?
Fluids have different densities. This means that the same quantity of two different fluids will not necessarily weigh the same. Whereas a liter of water weighs almost exactly one kilo, a liter of syrup is heavier because in addition to water it also contains a large amount of dissolved sugar. As you saw in the experiment, the syrup drops to the bottom and the mineral water floats upwards. This is because fruit juice is denser than water but less dense than syrup. That’s why, if you’re careful, you can pour a layer of water onto the juice.
The coconut milk also floats on the fruit juice. It contains a lot of fat, which allows it to float on watery liquids.