Topsy鈥檚 Experiments
The rainbow drink
Liquids can also be layered on top of each other. It鈥檚 not magic, just simple physics!
What you鈥檒l need
What you鈥檒l need
- A tall, narrow glass
- A long-handled spoon
- Orange or multi-vitamin juice
- Red syrup (e.g., raspberry)
- Small marshmallow pieces
- Smarties庐
- 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
1. Fill the tall, narrow glass two-thirds full with fruit juice.
2. Carefully pour a little syrup into the glass with the fruit juice.
Variation A: 3. Pour some mineral water into the other water glass and add a dash of blue food coloring.
Variation A: 4. Stir the liquid carefully so that the water does not lose its fizziness.
Variation A: 5. Using the spoon, now pour the mineral water onto the fruit juice. The best way to do this is to hold the spoon over the edge of the glass just a little above the surface of the juice and to pour the water very carefully onto it, spoonful by spoonful.
Variation B: Alternatively, instead of the colored mineral water in step 5, you can pour a thin layer of coconut milk onto the juice. To do so, position the spoon just a little above the surface of the juice and pour the coconut milk onto it, spoonful by spoonful.
6. Now it鈥檚 time to decorate your drink. You can do this by carefully floating a piece of marshmallow on top and placing two to three Smarties庐 onto the marshmallow.
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庐 won鈥檛 float on the surface of the drink, but if you use a piece of marshmallow as a 鈥boat鈥 you can place two Smarties庐 on top and it won鈥檛 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鈥檚 why, if you鈥檙e 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.