CBSE Class 7 Science Changes Around Us: Physical and Chemical (Class 7 NCERT New) Quiz 2

1. What happens to the particles during a chemical change?

A Particles rearrange themselves to form new substances. B Particles disappear completely C Particles remain unchanged D Particles transform into energy

2. In what way do reversible changes differ from irreversible changes?

A Reversible changes can be undone, while irreversible changes cannot. B Reversible changes cannot be observed, while irreversible changes can. C Reversible changes always lead to a decrease in entropy, while irreversible changes do not. D Reversible changes are faster than irreversible changes.

3. Why is it important to understand the different types of changes?

A Understanding changes is not important B All changes are the same C It is important to understand the different types of changes to anticipate, plan for, and adapt to them effectively. D Ignoring changes leads to success

4. Discuss the impact of irreversible changes on the environment.

A Irreversible changes on the environment have significant and lasting negative impacts on ecosystems, biodiversity, and human societies. B Reversible changes have a more significant impact on the environment C Irreversible changes do not affect ecosystems D The impact of irreversible changes on the environment is temporary

5. How can you reverse a reversible change?

A Ignore the change and hope it reverses itself B Apply the same actions that caused the change C Perform the opposite actions that were done to make the change D Ask someone else to reverse the change

6. Which of the following is a physical change?

A Rusting of iron B Melting of wax C Combustion of magnesium ribbon D Burning of candle

7. A chemical change may involve

A Change in color only B Change in temperature only C Evolution of gas only D Any or all of the above

8. Which of the following processes is used to prevent articles from rusting?

A Crystallization B Galvanization C Evaporation D Electolysis

9. Which of the following changes is accompanied by sound?

A Photosynthesis B Spoilage of food C Explosion of fire works D Crumpling of paper

10. A change is a chemical change when it is accompanied by:

A energy change B formation of new substances C change in chemical properties D all of the above