CBSE Class 7 Science Changes Around Us: Physical and Chemical (Class 7 NCERT New) Quiz 1

1. What is a physical change?

A A physical change involves a change in the state of matter. B A physical change is a change in the chemical composition of matter. C A physical change is reversible. D A physical change is a type of change in which the form or appearance of matter changes, but its chemical composition remains the same.

2. Give an example of a physical change.

A Burning wood into ash B Boiling water into steam C Freezing water into ice D Melting ice into water

3. Define a chemical change.

A A chemical change is a process that involves physical changes only. B A chemical change is a process that does not involve any transformation. C A chemical change is a process in which one or more substances are converted into different substances with different properties. D A chemical change is a process where substances remain the same.

4. Provide an example of a chemical change.

A Cutting a piece of paper B Boiling water C Mixing salt and sugar D Iron rusting

5. Explain what a reversible change is.

A A reversible change is a change that is always permanent. B A reversible change is a change that cannot be undone. C A reversible change is a change that can be undone or reversed. D A reversible change is a change that only happens once.

6. Can you give an example of a reversible change?

A Mixing salt in water B Burning paper into ashes C Boiling water into steam D Melting ice into water and freezing the water back into ice

7. Describe an irreversible change.

A An irreversible change can be reversed easily B An irreversible change is a change that cannot be undone or reversed to its original state. C An irreversible change has no impact D An irreversible change is temporary

8. Share an example of an irreversible change.

A Burning a piece of paper B Freezing water C Mixing salt in water D Melting ice cream

9. How can you identify a physical change?

A Check if the change produces a new substance B Observe if the change alters the substance's physical state C Verify if the change affects the substance's color D Observe if the change can be reversed without altering the substance's chemical composition.

10. How can you distinguish a chemical change from a physical change?

A Chemical changes are reversible, while physical changes are not. B Chemical changes involve the formation of new substances, while physical changes do not. C Physical changes always involve a change in color, while chemical changes do not. D Physical changes involve the formation of new substances, while chemical changes do not.