Everything around us keeps changing. Ice cream melts, clothes dry in sunlight, vegetables are cut while cooking, and water boils for tea. Some changes only affect how things look, feel, or exist in different forms. These are called physical changes.
Physical changes happen every day in our homes, schools, and surroundings. They are easy to observe and understand.
What is a Physical Change?
A physical change is a change in which only the physical properties of a substance change. These properties include:
- Shape
- Size
- State (solid, liquid, gas)
- Sometimes texture or appearance
During a physical change:
- No new substance is formed
- The original material remains the same
- The change is often reversible
A physical change is a change that affects only the form or appearance of a substance without changing it into a new substance.
Characteristics of Physical Change:
1. No New Substance is Formed
The substance before and after the change remains the same.
Example:
Ice melts into water.
Ice and water are both the same substance – water.
Ice and water are both the same substance – water.
Melting of ice cubes
2. Change in Shape
The object may change its form.
Examples:
- Folding paper into a boat
- Rolling dough into chapati
- Breaking chalk into pieces
Dough
3. Change in Size
The object may become bigger or smaller.
Examples:
- Cutting vegetables into smaller pieces
- Sharpening a pencil
- Inflating a balloon
Inflated and deflated balloon
4. Change in State
Matter may change from one state to another.
Examples:
- Ice → Water (solid to liquid)
- Water → Steam (liquid to gas)
- Water → Ice (liquid to solid)
5. Usually Reversible
Many physical changes can be changed back.
Examples:
- Water freezes back into ice
- Melted wax becomes solid again
- Folded paper can be unfolded
Is Burning Paper a Physical Change?
No.
Because burning paper forms ash, smoke, and gases. New substances are formed. So burning paper is not a physical change.
Is Boiling Water a Physical Change?
Yes.
Because water changes only from liquid to steam and remains water.