Each Tuesday afternoon I get to spend time with my precious Abigail. We usually do some chemistry together from MEL Science. Abigail has a monthly subscription (her Christmas present this year). This week we created a soap boat from her second MEL Chemistry box, all about rocket science.
Soap Boat: The Box
Abigail is sent one box per month which contains at least two different experiments. This month’s box was all about rocket science, and contained absolutely EVERYTHING to make a Soap Boat and a Test Tube Rocket:
Soap Boat: Preparation
Abigail treats these experiments with a little more seriousness than her Curiosity Box Science, which she does alone. With her MEL science she always wears her lab coat, and always has gloves and goggles at the ready:
Soap Boat: Method
In addition to the website instructions, MEL Science also provides each student with a small card with very clear step by step instructions on how to do the experiment.
- First, Abigail places the water in a wide bowl or tray:
- Next, she spreads the boat sides apart:
- Then, she places the boat at the side of the tray:
- Lastly, she adds one drop of liquid soap inside the hole on the boat:
Soap Boat: Results
- The boat speeds across the surface of the water:
- Abigail experiments by turning the boat around and timing how long it will move on one drop of liquid soap
Soap Boat: Conclusion
Water molecules are highly attracted to each other, meaning that the surface tension of the water is strong. If the tiny boat is placed on top of the water, the same forces apply but in equal amounts all around the edges of the boat. It therefore does not move.
The liquid soap breaks the intermolecular bonds, decreasing water tension. In this experiment, the liquid soap is directed only at the back of the boat. It therefore only breaks the bonds at the back which creates a pull forward. The boat moves forward.
Explaining to others what you have done is a great way to test understanding. Here, Abigail is attempting to explain what happened when she added the liquid soap:
Extending the Fun
There was an extra boat included, so Abigail persuaded Becca to have a boat race in the bath 🙂
Too much fun!
Becs won. Abigail was less than impressed!
The next experiment is a test tube rocket. Fun times ahead!
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