NCERT Chemical Changes Objective Questions
NCERT Chemical Changes – Objective Questions (MCQs)
Class: 7 | Subject: Science | Section: Physical & Chemical Changes | Topic: NCERT Chemical Changes Objective Questions
Based Strictly on NCERT Syllabus | CBSE Board Examination Pattern
Based Strictly on NCERT Syllabus | CBSE Board Examination Pattern
1. A chemical change always results in:
Answer: B. Chemical changes produce entirely new substances with different properties.
2. Burning of coal is a:
Answer: B. Burning forms ash, carbon dioxide and heat.
3. Which is NOT a chemical change?
Answer: C. Boiling only changes state.
4. Formation of gas indicates:
Answer: B. Gas evolution shows new substance formation.
5. Digestion of food is:
Answer: B. Food converts into new simpler substances.
6. Explosion of fireworks is a chemical change because:
Answer: D. Multiple evidences confirm chemical change.
7. Which shows colour change due to chemical reaction?
Answer: A. Iron turns reddish‑brown.
8. Photosynthesis is a chemical change because:
Answer: D. New substances form using energy.
9. Chemical changes are usually:
Answer: B. Original substance cannot be regained easily.
10. Which is a sign of chemical change?
Answer: D. All indicate reaction.
11. Curd formation involves:
Answer: B. Lactobacillus converts milk chemically.
12. Tarnishing of silver is due to:
Answer: B. Silver sulphide forms.
13. Baking a cake is:
Answer: B. Irreversible formation of new product.
14. Respiration is a chemical change because:
Answer: D. Complex biochemical reaction.
15. Which is reversible chemical change?
Answer: C. Few reactions can reverse under special conditions.
16. Chemical change involves change in:
Answer: D. Substance becomes entirely new.
17. Which is fastest chemical change?
Answer: C. Explosions occur instantly.
18. Which does NOT indicate chemical change?
Answer: C. Size change alone is physical.
19. Fermentation is a:
Answer: B. Sugars convert into alcohol/acids.
20. Chemical changes are useful in:
Answer: D. They are essential in daily life and industry.