Bubble Science For Kids: Fun Surface Tension Experiments with Bubble Blowing

Exploring with bubbles is a great STEM activity for a sunny day.  You can even create a bubble lab for students inside.  Soap is easy to find, and many things can be used as bubble blowers.  As a science teacher, I expand my focus to the science behind the bubbles, focusing on surface tension.

What is the Structure of a Bubble?

A soap bubble is composed of 3 layers.  The middle layer is water, which is sandwiched between 2 layers of soap.  Soap has two ends.  One is attracted to oil, and the other end is attracted to water.  The outer layer of a bubble contains the oil-loving soap ends.  This is why a bubble pops when it touches another object.  The object is most likely covered in oil and dirt.  Since the outer layer is attracted to oil, it clings to the object and pops.  If the object is free of oil and dirt, the bubble may sit on top of the object.  Eventually, the bubble will begin to evaporate and then pop.

Why is a Bubble Round?

No matter what shape you start with, when you blow a bubble, it will make a sphere.  Bubbles always form the shape with the smallest surface area.  A sphere has less surface area and is more stable than other shapes.

How to Catch a Bubble (Easy and Quick Experiment)

A wet object does not take anything away from the bubble.  Dip your hand in soapy water to catch a bubble.  When your hand is wet, the soapy water attracts to the bubble.  Your hand becomes part of the netting instead of creating gaps.  The bubble will sit on your hand.  Remember to wash your hands before trying this trick.  

Supplies

Tub of Soapy Water, Bubble Blower, A Clean Hand, Paper Towels

Steps

1. Purchase or create a bubble solution.  You can also try our free download below. You want enough to submerge your hand.

2. Wash your hands.

3. Dip your bubble blower in the soap and blow a bubble.  Try to catch it on your dry hand. What happened?

A dry hand absorbs the water in the bubble.  Your dry hand likely contains oil and dirt.  When you touch the bubble, your skin creates a gap between the soap bubble molecules.  Think of a bubble like a net.  If the molecules are too far apart, they can not stay together.  The attraction to oil in your hand causes the soap bubble to cling to your hand, increasing this gap.  When the gap is too far apart, the bubble pops.

4. Now, dip your hand in the soapy water. Blow another bubble and try to catch it with your soapy hand. What happened?

A wet object does not take anything away from the bubble.  Dip your hand in soapy water to catch a bubble.  When your hand is wet, the soapy water attracts to the bubble.  Your hand becomes part of the netting instead of creating gaps.  The bubble will sit on your hand.  Remember to wash your hands before trying this trick.  

5. Expand further by testing how long the bubble stays on your hand.  How big a bubble can you hold? Do all soaps work the same?  

Free Bubble Recipe

Bubble STEM Explorations for the Classroom

There are many things you can do with bubbles. Did you know bubbles will move due to static electricity? Check out the list of activities below to help you create a complete soap-and-water science unit. These activities explore surface tension, molecular structure, the properties of water, and more.

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