What happens when you apply shampoo to a toothpick in a pool of water? We’re back with another chemistry Science lesson that will teach your kids at home about Surface Tension! This is the ‘Turbo Toothpick’ experiment, a very simple but enjoyable science trick using only a few things: You will need:

• At least one wooden toothpick
• A plate or tray
• Water
• Shampoo

Method:

• Taking your plate or tray, you’ll first want to fill it with water so that you have a shallow pool for your toothpick to float on. Place your pool of water on a hard surface.
• Next up, squeeze out a bit of shampoo and dab a bit of it on your finger. What happens when you put your finger in the pool of water?
• Now let’s try applying it to the toothpick. Repeat the same process again, but this time dab a small amount of shampoo onto the tip of your toothpick. What happens when you place the toothpick into the pool of water? You should find that the toothpick starts to travel, with the end of the toothpick covered in shampoo boosting the toothpick along in the opposite direction.
• And that’s the ‘turbo toothpick’ experiment in a nutshell – However, the fun’s not over yet! If you’ve got plenty more toothpicks at hand, you can turn each one of them into ‘turbo toothpicks’ and race them against each other. Why not try different sized toothpicks or different amounts of shampoo? What works best and what doesn’t?

The Science Bit: The experiment may have been simple, but what about the Science behind it? Just like last week, this experiment explorers surface tension. After the wooden toothpick is placed in the water, the shampoo on the end of it starts to dissolve and it reduces the water’s surface tension around it. This is because most shampoos contain agents that are able to reduce the surface tension of liquids. As a result of this, the water’s hold on the end of the toothpick disappears and the toothpick is pushed in the direction of the end that still has surface tension applied to it. And thus, the wooden skewer is propelled forwards. That’s all from us this time and we hope you enjoyed another fun Science experiment at home!