We see changes all around us. The rusting of an iron object, the ripening of fruit, making of ice cubes, breaking of glass, baking of a cake, the burning of firewood or the souring of milk can teach us a lot about the types of changes that take place around us. I usually include such daily-life examples in homeschool curriculum so that children can learn using everyday occurrences and at the same time know why things change.
When you make ice out of water in a refrigerator, a new substance is not formed. The substance is the same: water. The only difference is that it has changed from liquid state to solid state. This change can be reversed by melting the ice cubes back into water. This type of change is called physical change.
When firewood burns, it turns into ash, a new substance. Furthermore, it is impossible to change ash back into wood. Therefore it is a chemical change. These are all occurrences that your child has experienced, and they can bring alive the homeschool curriculum.
When a fruit ripens, there is a change in taste and color, indicating that there has been some chemical change. A ripe fruit cannot become raw again, making this an irreversible change. What types of change occurs when glass breaks, when iron rusts or when milk sours?
The following experiment can teach us about change and lots more.
The Microwave Soap Experiment: You will need an Ivory soap for this experiment. Other soaps will not work as well or may not work at all. Take a microwave-safe dish and place a bar of Ivory soap on it. Place the dish in a microwave oven and run the oven for two to three minutes. Something magical happens!
You will notice that beginning from the point where the microwaves converge, the soap begins to foam. The volume of the foam increases within the next minute or so, and becomes about five times the volume of the soap bar. Don’t touch the soap till it cools down.
Your eyes saw a change. Now touch the soap and find out if it was a physical change or a chemical change. Has the substance changed? Use it with some water and find out if the properties have changed.
When the microwaves heat up the air and water contained in the soap, air expands and water turns into vapor. The soap, which is softened by now, expands while trapping air bubbles inside it. As the soft soap expands it forms foam. This is a quick and safe experiment that could add meaning to your homeschool curriculum.
Now compare the above experiment to the baking of a cake. When you bake a cake, you mix flour, eggs, essence, sugar and other ingredients into the batter. The end product is something new: a delicious cake. Now, you cannot get the sugar or the eggs or the flour back in their original form. This irreversible reaction is called a chemical reaction.
Check out the free “Homeschool Parent’s Guide to Teaching Science”, for more great science experiments and activities, click the link below.
If you are looking for some great free science experiments and activities, one of my personal favorites is the Homeschool Science Experiment Guide.
About the Author Aurora Lipper has been teaching science to kids for over 10 years. She is also a mechanical engineer, university instructor, pilot, astronomer, a real live rocket scientist (You should see the lab in her basement!) and a mom. She has inspired thousands of kids with the fun and magic of science.