Question

Give an example of a physical change and explain the mechanism?

Answer 1

Physical change :

• The change in which only the physical properties of the substance change, but its chemical composition remains unaffected.
• During the physical change, the physical properties such as temperature, colour, density, volume, melting or boiling point, shape, and size only get altered.
• A physical change is generally temporary and reversible in nature. Also, no new substance is formed during the physical change process.
• Examples are melting a cube of ice, boiling water, crushing a can, cutting papers, mixing sugar and water, etc.

Example with the mechanism:

• Take a smooth sheet of paper and crumble or crush it into a ball. We can also fold it or make any paper toy from it.
• But in all these forms only the size or shape of the paper got changed which are physical properties, but the chemical composition remains the same.
• No new substance formed during the process, hence it is an example of physical change.

Hence, an example of a physical change is crumbling a paper sheet where we have noticed no chemical properties have been altered.