Carefully review the general safety advice on the back of the box cover before starting the experiment.
Perform the experiment on the safety tray and use protective gloves to avoid staining your hands.
Never eat or drink any of the substances provided. Do not use for culinary purposes.
Wear protective gloves and use the waterproof underlay to keep your table clean. To open a bottle, push the cap down and turn it. Use a paper clip to pierce the bottle nozzle.
The two pieces of felt in this set have different wetting properties: one is hydrophilic, which means it tends to absorb water, and the other is hydrophobic, so water will be repelled from its surface.
The hydrophobic powder’s attraction to water molecules is very weak, so drops of water will slide off of it easily. Let’s prepare a card with both hydrophobic and hydrophilic areas.
The areas of the card that didn't retain the hydrophobic powder will absorb water. Try to lead a single drop from the start to the finish by tilting the card.
Repeat steps 3 and 4 with the other card, and try to navigate a more challenging labyrinth!
Dispose of solid waste together with household garbage.
Pour liquids down the sink. Wash with an excess of water.
In the first experiment, you observed that a droplet spreads differently on different surfaces. On hydrophilic surfaces , a water drop adopts the widest possible shape or is completely absorbed, sinking into the material’s pores. On hydrophobic surfaces , conversely, it tends to touch the surface as little as possible .
Once coated with a hydrophobic powder , the card attracts water molecules weakly. In each drop, the outer layer of water molecules holds the remaining molecules inside, keeping the drop in a spherical form . Since the water droplets are weakly attracted to the surface of the card, they can easily roll along the surface just as a ball rolls across a floor.
Dozens of experiments you can do at home
Kids are now able to engage with science in a way that they simply wouldn’t have been able to in the past as they shrink themselves down to see the world at a molecular level