Easy Science Experiments for Kids – Surface Tension

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. For example, we love the dancing milk experiment and love doing experiments with try ice! 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.

Materials

• Scissors
• Card stock
• Bowl*
• Water
• 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

Approach

• 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 fingertip 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 front of the “boat”.
• Use different liquids
• Experiment with different substances in the water (black pepper, for example, gives a great demonstration of soap deterring germs
• Utilize 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