What is a physical change? A physical change happens when matter changes in size, shape, or state, but no new substance is formed. In this guide, kids will learn the physical change definition, explore everyday examples of physical change, compare physical vs chemical changes, and try hands-on physical change experiments that make science easy and fun to understand.
What Is a Physical Change?
A physical change is a change in matter that does not change what the substance is made of.
During a physical change, the atoms and molecules stay the same. The material may look different or behave differently, but it remains the same substance. No new material is created.
Physical Properties That Can Change
Physical changes often involve a change in one or more physical properties, including:
- Color
- Density
- Mass
- Solubility
- State (solid, liquid, gas)
- Temperature
- Texture
- Viscosity
- Volume
Examples of Physical Change
These examples show physical changes in which the substance remains the same, even though its appearance or state changes.
Physical properties describe matter without changing it; see our Physical Properties of Matter for Kids guide for more.
💡 Understanding physical changes helps explain how matter behaves in everyday situations and in fields like science, engineering, and materials science.
Physical Change vs Chemical Change
A physical change is different from a chemical change.
A chemical change occurs when matter turns into one or more new substances. This means the particles rearrange to form something completely different.
- Burning wood is a chemical change because it produces ash and gases that are not the same as the original wood.
- Chopping wood into smaller pieces is a physical change because the wood remains wood, just in a different form.
Are Physical Changes Reversible?
A helpful question for kids to ask is: Can this change be reversed?
Many physical changes are reversible, especially changes in state such as melting, freezing, evaporation, and condensation.
Some physical changes are not easy to reverse. For example, shredded paper is still paper, but it is very difficult to turn it back into a whole sheet. Chemical changes are usually not reversible.
Everyday Examples of Physical Change
Physical changes happen all around us every day.
- Boiling water
- Adding milk to cereal
- Cooking pasta until it softens
- Chewing candy
- Chopping vegetables
- Grating an apple
- Melting cheese
- Slicing bread
- Washing clothes
- Sharpening a pencil
- Using an eraser
- Crushing a box for recycling
- Steam fogging a mirror
- Ice forming on car windows
- Mowing the lawn
- Drying clothes in the sun
- Making mud
- A puddle drying up
- Trimming trees
- Adding salt to water
Guiding Questions to Explore Physical Changes
These guiding questions help kids think like scientists as they observe physical changes in everyday materials.
- What changes can you see when matter changes shape, size, or state?
- Does the material stay the same after the change?
- Is a new substance formed, or does the matter remain the same?
- Can the change be reversed?
- How can you tell if a change is physical or chemical?
Scientists use questions like these to investigate how matter behaves and to classify different types of changes
Physical Change Experiments for Kids
These hands-on experiments help kids observe physical changes in action by changing size, shape, state, or physical properties — without creating a new substance.
Crushed Can Experiment
Observe how changes in air pressure can crush a can without changing the material it is made from.
Dissolving Candy
Watch candy dissolve in water as the coating spreads through the liquid without forming a new substance.
Magic Milk
Adding dish soap breaks surface tension in milk, creating swirling patterns caused by physical interactions between molecules.
Freezing Water Experiment
Explore how water changes from a liquid to a solid while remaining the same substance.
Ivory Soap Experiment
Heating ivory soap causes it to expand dramatically, showing a physical change in size and structure.
Making Recycled Paper
Transform old paper into new paper by changing its texture and appearance without altering the material itself.
Melt-and-Pour Soap Making
Melting and reshaping soap demonstrates a reversible physical change using heat.
Melting Ice Experiments
Investigate what makes ice melt faster and observe a change in state from solid to liquid.
Melting Crayons
Use heat to melt old crayons and form new shapes while keeping the material the same.
Paper Towel Art
Ink and water spread through paper fibers, showing a physical change through absorption.
Popcorn in a Bag
Heat causes water inside popcorn kernels to turn to steam and pop the corn in a physical change.
Rainbow in a Jar
Adding sugar to water changes the density of the liquid, allowing colorful layers to form.
Separating Mixtures
Use physical methods like filtering or sorting to separate substances without changing them.
Salt Water Density Experiment
Adding salt changes the density of water and affects whether objects float or sink.
Skittles Experiment
Candy colors spread through water due to dissolving and diffusion without mixing.
Solid, Liquid, Gas Experiment
Observe matter changing between states while remaining the same substance.
Thermochromic Slime
Temperature causes the slime to change color, showing a reversible physical change.
What Absorbs Water
Test different materials to see how absorption affects size, texture, and volume.
What Melts
Compare how quickly different materials melt in the sun and observe physical changes caused by heat.
Physical Changes That Look Like Chemical Reactions
Some physical changes look like chemical reactions because they fizz or move, but no new substance is formed.
Dancing Raisins
Carbon dioxide bubbles attach to raisins, causing movement without a chemical change.
Diet Coke and Mentos
Gas rapidly escapes from the soda, creating an eruption through a physical process.
Pop Rocks and Soda
Trapped gas is released when Pop Rocks dissolve, producing bubbling and foam.
Free Physical Change Guide
Start exploring physical change with this free information guide.
Frequently Asked Questions About Physical Changes
What is a physical change?
A physical change happens when matter changes in size, shape, or state, but the substance itself stays the same and no new material is formed.
What is an example of a physical change?
Freezing water is a physical change because the water turns from a liquid into a solid while remaining water.
Is dissolving sugar a physical change?
Yes. Dissolving sugar is a physical change because the sugar particles spread out in the water but do not change into a new substance.
How is a physical change different from a chemical change?
A physical change does not create a new substance, while a chemical change forms one or more new substances.
Are physical changes reversible?
Many physical changes are reversible, especially changes in state like melting and freezing. Some physical changes, such as shredding paper, are not easy to reverse.
Related Chemistry Concepts to Explore
- What is matter?
- States of matter
- Chemical changes
- Phase Changes
- What is an Element?
- What is a molecule? (coming soon)
- Chemistry activities and experiments
Want even more hands-on ideas? Browse our full collection of science experiments and activities for kids.
Printable Science Packs for Kids
Visit our SHOP for easy-to-print STEM and science lesson plans for the whole year. Or join us in the Little Bins Club.
