What is a chemical change? A chemical change happens when matter reacts and forms one or more new substances with different properties from the original materials. In this guide, kids will learn the chemical change definition, explore everyday examples of chemical change, compare chemical vs physical changes, and investigate hands-on chemical change experiments using common household materials.
What Is a Chemical Change?
A chemical change occurs when substances react and turn into new substances with different chemical and physical properties.
During a chemical change, the atoms rearrange to form new molecules. Because new substances are created, chemical changes are usually permanent and not easy to reverse.
A chemical change is also called a chemical reaction.
How Chemical Changes Happen
Chemical changes often involve noticeable signs that a reaction has taken place. These may include changes in color, temperature, smell, or the production of gas or light.
Energy is often released or absorbed during a chemical reaction. Some reactions give off heat or light, while others require energy to occur.
Chemical Change vs Physical Change
A chemical change is different from a physical change.
A physical change affects the form, size, or state of matter but does not create a new substance. The material stays the same. Melting crayons is a perfect example!
A chemical change creates a new substance with different properties from the original materials. Homemade fizzing slime (as shown below) is a fantastic example.
For example, rusting iron is a chemical change because iron reacts with oxygen to form iron oxide, which is a new substance. Cutting iron into smaller pieces is a physical change because the iron itself does not change.
Guiding Questions to Explore Chemical Changes
These guiding questions help kids think like scientists as they observe chemical changes in everyday materials.
- What signs show that a new substance has formed?
- Does the material change into something different?
- Is energy released or absorbed during the change?
- Can the change be reversed easily?
- How can you tell if a change is chemical or physical?
These questions encourage observation, comparison, and scientific thinking without requiring advanced vocabulary.
Everyday Examples of Chemical Change
Chemical changes happen all around us in daily life.
- Burning wood
- Baking a cake
- Frying a steak
- Boiling an egg
- Burning a candle
- Lighting a match
- Rusting nails
- Washing hands with soap
- Fermentation
- Souring milk
- Photosynthesis
- Digesting food
- Banana rotting
- Chemical batteries
- Running a lawnmower
Chemical Change Experiments for Kids
These hands-on experiments help kids observe chemical changes by creating new substances through safe, controlled reactions using common materials.
Alka-Seltzer Rocket
A chemical reaction produces carbon dioxide gas, creating pressure that launches the rocket.
Apple Browning Experiment
Cut apples react with oxygen in the air, forming new substances that cause browning.
Balloon Experiment
A baking soda and vinegar reaction produces gas that inflates a balloon.
Bath Bombs
Citric acid and baking soda react in water, releasing gas and creating fizz.
Baking Powder Science
Adding liquid triggers a chemical reaction that produces gas used in baking.
Bottle Rocket
Gas produced by a chemical reaction builds pressure and launches the bottle.
Bread in a Bag
Yeast reacts with sugar to produce carbon dioxide, causing the dough to rise.
Carbon Sugar Snake Experiment
Heat causes sugar and baking soda to react and form a carbon structure.
Citric Acid Experiment
Acids react with baking soda to produce gas and visible bubbling.
Cranberry Experiment
Baking soda reacts with acidic juices, producing fizzing bubbles.
Egg in Vinegar (Rubber Egg)
A chemical reaction removes the eggshell, leaving behind a rubbery egg.
Elephant Toothpaste
An exothermic reaction rapidly produces foam and releases heat.
Green Pennies
Copper reacts with chemicals to form a new patina on the surface.
Invisible Ink
A chemical reaction reveals hidden writing when heat or another substance is applied.
Lava Lamp Experiment
A chemical reaction produces gas bubbles that move through oil and water.
Milk and Vinegar (Plastic Milk)
Milk proteins react with acid to form a solid plastic-like substance.
Popping Bags
Gas produced during a chemical reaction builds pressure until the bag bursts.
Potato Battery
Chemical reactions between metals and electrolytes generate electrical energy.
Slime
Ingredients react to form a new stretchy polymer substance.
Yeast Fermentation
Yeast converts sugar into carbon dioxide and alcohol during fermentation.
Volcano Experiments
Baking soda and vinegar react to create gas and erupting foam.
Frequently Asked Questions About Chemical Changes
What is a chemical change?
A chemical change happens when substances react and form one or more new substances with different properties.
What is an example of a chemical change?
Rusting iron is a chemical change because iron reacts with oxygen to form iron oxide, a new substance.
How can you tell if a change is chemical?
Signs of a chemical change include color changes, gas production, temperature changes, odors, or light.
Is boiling water a chemical change?
No. Boiling water is a physical change because the water changes state but remains the same substance.
Is frying an egg a chemical change?
Yes. Heating an egg causes proteins to change their structure, forming new, permanent substances.
FREE Chemical Change Guide to get started!
Examples of chemical changes are provided in this free printable chemical changes guide.
Related Chemistry Concepts to Explore
- Chemistry activities and experiments
- What is matter?
- States of matter
- Physical changes
- Phase Changes
- What is an Element?
- What is a molecule? (coming soon)
Want even more hands-on ideas? Browse our full collection of science experiments and activities for kids.
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