Homeschool STEM activities are a wonderful way for your child to explore a wide variety of science topics, from learning about scientific inquiry to what happens when you mix an alkaline and an acid.
If you are looking for a simple science experiment that feels like magic while teaching real scientific concepts, the Ivory soap experiment is one of the best hands-on activities you can try. And that is what I am sharing with you today.

Using just a bar of Ivory soap and a microwave, kids can watch an ordinary soap bar transform into a giant fluffy cloud right before their eyes. It is quick, inexpensive, easy to clean up, and perfect for homeschool science lessons, rainy afternoons, or family fun nights.
Children get excited because they are able to see chemistry and physics happening in real time.
The dramatic change in size captures their attention immediately, creating an excellent opportunity to spark a conversation about how matter changes.
BOOKS ABOUT NOTABLE STEM FIGURES
First, add a few of these books about famous STEM figures.
We prefer living books. Add a few to your home library.
8 Notable STEM Figures
Add some of these books to your reading day about science and famous inventions.
Charles Ludwig retells Michael Faraday’s remarkable life story in fictionalized form. Here is the father of the electric motor, the dynamo, the transformer, the generator. Few persons are aware of the brilliant man’s deep Christian convictions and his determination to live by the Sermon on the Mount. For ages 12 to 15.
Einstein's astonishing theory of relativity transformed every aspect of physics-from the study of atoms to the study of stars. Relativity is described here in simple, accurate language that young readers can comprehend.
Electrical engineer and inventor Nikola Tesla (1856–1943) was indeed an electrical genius. In language suitable for both young and old, author Arthur J. Beckhard describes all aspects of Tesla’s personal and professional life, including Tesla’s childhood and his education at primary school, at the Higher Real Gymnasium, and at the Polytechnic Institute; his years working for the telegraphic engineering department of Austria, then as an engineer in Paris, and then as an employee of Thomas Edison in America; his substitution of alternating current for direct current—a simpler and more economical method of converting electrical into mechanical energy; his rotary magnetic field, which was used in transmitting the power of Niagara Falls to nearby cities; his independent research at his own electrical laboratories in New Your City; and much more. Originally published in 1959 as part of Messner Publications' "Men of Science" series
Before John Glenn orbited the earth, or Neil Armstrong walked on the moon, a group of dedicated female mathematicians known as “human computers” used pencils, slide rules, and adding machines to calculate the numbers that would launch rockets, and astronauts, into space.
This book brings to life the stories of Dorothy Vaughan, Mary Jackson, Katherine Johnson, and Christine Darden, who lived through the Civil Rights era, the Space Race, the Cold War, and the movement for gender equality, and whose work forever changed the face of NASA and the
country.
As a young girl, Katherine Johnson showed an exceptional aptitude for math. In school she quickly skipped ahead several grades and was soon studying complex equations with the support of a professor who saw great promise in her. But ability and opportunity did not always go hand in hand. As an African American and a girl growing up in an era of brutal racism and sexism, Katherine faced daily challenges. Still, she lived her life with her father’s words in mind: “You are no better than anyone else, and nobody else is better than you.”
Computers touch our lives everyday, in countless ways, but how do they know what to do? How do we communicate with them and they with each other? Language! Grace Hopper was a pioneer in computer programming, a woman whose scientific research led to computer-language tools and technology still in use today. Her story is filled with trial and error, and readers can follow the journey step by step.
Jane Goodall, born in London, England, always loved animals and wanted to study them in their natural habitats. So at age twenty-six, off she went to Africa! Goodall's up-close observations of chimpanzees changed what we know about them and paved the way for many female scientists who came after her. Now her story comes to life in this biography with black-and-white illustrations throughout.
Can you imagine how different life would be without the printing press? It's unlikely you'd ever have held a book. And your clothes would look very different without the invention of spinning and sewing machines. Without boats, trains, and planes, even our diets would be changed.Read about the fascinating creators of these inventions and the struggles they faced. Some got rich, some fought for every penny, but they all changed the way we live our lives today. Inventors profiled in this collection include James Watt (the steam engine), Elias Howe (the sewing machine), Cyrus McCormick (the reaper), John Gutenberg (the printing press), Alexander Graham Bell (the telephone) as well as many more.This reprinting is complete and unabridged featuring all the original illustrations and reformatted text for easier reading.
Then, here are more fact about the Ivory soap experiment.
ABOUT THE IVORY SOAP ACTIVITIY
To explain simply how this works, Ivory soap contains tiny air pockets that are whipped into the soap during manufacturing. In fact, Ivory soap is famous for floating in water because of the air trapped inside.
When the soap is heated in the microwave, the air and water molecules inside begin to expand rapidly. The heat softens the soap while the expanding air pushes outward, and this causes the soap to puff up into a giant foam structure.
This experiment demonstrates several scientific concepts, including expansion caused by heat, physical changes in matter, air trapped inside materials, and how microwave energy interacts with water molecules. It is a wonderful visual example of how heat can change the properties of a substance.

To keep them engaged, have older kids research why microwaves heat water molecules or compare the results between different soap brands.
For younger children, this experiment encourages observation skills, prediction-making, and sensory exploration. It is especially engaging for those hands-on learners who benefit from seeing science in action rather than simply reading about it.
MORE THAN A KITCHEN SCIENCE ACTIVITY
Children do not expect a hard soap bar to grow into a giant, fluffy sculpture. The rapid transformation creates excitement and wonder, which is exactly what makes science meaningful and fun.
Experiments like this also help children connect learning with everyday life. They begin to realize that science is not limited to textbooks or laboratories. It can happen right in the kitchen using ordinary household items.
The Ivory Soap Experiment is more than just a fun kitchen activity. We can use it to introduce vocabulary words and scientific thinking.
Here are a few questions to ask children during the experiment:
- What do you think will happen to the soap?
- Why does the soap get bigger instead of melting flat?
- How does the texture change after heating?
- Is this a physical change or a chemical change?
MORE AMAZING HOMESCHOOL STEM ACTIVITIES
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- 3 Easy Penguin Activities And Penguin Slide STEM Activity
- How to Make Awesome Tin Can Wind Chimes | KidMinds
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Now look at how to do this activity.
IVORY SOAP EXPERIMENT
You will need:
- One bar of Ivory soap
- A microwave-safe plate
- A microwave
- Optional: safety gloves or oven mitts

Start by placing the bar of Ivory soap on a microwave-safe plate. You can use the whole bar or cut it into smaller pieces if you prefer.

Put the plate in the microwave and heat the soap for about one to two minutes.

Watch carefully through the microwave window as the soap begins to puff up dramatically.

Within seconds, the soap expands into a large, soft, cloud-like structure that looks almost like whipped foam.

Once the microwave stops, allow the soap to cool slightly before touching it. The texture becomes light, crumbly, and surprisingly airy.
Kids love exploring the finished product because it feels completely different from the original solid bar. Let them scratch it with fingernails, skewers, crumble it apart with their hands, and observe it under a magnifying glass.

The expanded soap can then be used after the experiment for sensory play or used over time as a gigantic fun soap to wash hands with.
A few tips for success…
- Use only Ivory soap for the classic fluffy effect; other brands don’t produce the same reaction.
- Watch the experiment carefully while microwaving; do not overheat the soap. One to two minutes is usually enough.
- Allow the soap to cool before handling.
- Place a paper towel under the plate for easier cleanup if desired.
