As you can probably guess from all my science related posts lately, my sons are a bit, shall we say, obsessed with science experiments right now. So, I grabbed one of my trusty resources, 101 Great Science Experiments, and searched for an easy and inexpensive activity. Sure enough I landed on perhaps the most perfect surface tension science experiment for kids.
Surface Tension Science Experiment for Kids
Science is hands on and fun for kids. The great part is that kids learn something while doing experiments that they enjoy! With a little bit of knowledge, you can easily bring this learning into your home and classroom.
- Card stock
- Dish soap
* I used a circular bowl first, then we used a longer pyrex bowl, which worked better because there was more space for the boat to speed off
- Cut a triangle from the card stock for your “boat”
- Fill your bowl with water*
- Gently place the triangle on top of the water (introduce the concept of surface tension)
- Place a small amount of dish soap on a finger
- Dip the finger tip into the water behind the “boat”
- Observe the boat speed off
- Encourage and ask questions
What to do next?
- Explain how the dish soap weakens the surface tension of the water. So, the tension is stronger in the front of the “boat”.
- Experiment with different liquids
- Experiment with different substances in the water (black pepper, for example, gives a great demonstration of soap deterring germs
- Experiment with different shapes (talk about velocity and physics)
- What happens with more dish soap? More water? A bigger “boat”?
- Have “boat” races
- Experiment with different objects to see if the water's surface tension can support various objects (such as a paper clip)
- Sink/Float work