ICSE Class 6 Chemistry - Introduction to Chemistry - Test 4 (Expert)
1. Heating a sample in a test tube produces gas bubbles. What does this indicate?
A. Chemical reaction is occurring
B. Physical change
C. No change
2. Water in a beaker disappears faster when heated. Why?
A. It is chemically reacting
B. Higher temperature increases evaporation rate
C. It freezes
3. A mixture of sand and water can be separated using:
A. Evaporation
B. Boiling
C. Filtration
4. Dew on leaves forms by:
A. Condensation
B. Evaporation
C. Sublimation
5. A solution changes colour during an experiment. What can be concluded?
A. Physical change
B. Chemical change
C. Temperature change only
6. Water boils at 100°C. What is observed in the experiment?
A. Freezing occurs
B. Physical change without bubbles
C. Formation of bubbles due to boiling
7. Iron filings are heated in a dry test tube. Will rust form?
A. No, water and oxygen are needed
B. Yes, heating alone is enough
C. Partially
8. Dry ice disappears directly into gas. This is called:
A. Evaporation
B. Sublimation
C. Condensation
9. Which method separates water from dissolved salt?
A. Filtration
B. Sedimentation
C. Evaporation/Distillation
10. What is essential in recording experimental results?
A. Accurate observation
B. Guesswork
C. Random notes
11. Wearing gloves and goggles in lab ensures:
A. Faster reaction
B. Safety from chemicals
C. Physical exercise
12. Sand mixed with sugar is a:
A. Compound
B. Element
C. Mixture
13. Oxygen (O₂) is an example of:
A. Element
B. Compound
C. Mixture
14. Water (H₂O) is a:
A. Mixture
B. Compound
C. Element
15. Salt can be separated from seawater by:
A. Filtration
B. Sedimentation
C. Evaporation
16. Cutting paper is an example of:
A. Physical change
B. Chemical change
C. Reaction with air
17. Burning wood produces ash and gases. This is a:
A. Physical change
B. Chemical change
C. Mixture
18. Indicators of a chemical reaction include:
A. Change in shape only
B. Change in volume only
C. Colour change, bubbles, heat
19. A solid changes colour and releases gas on heating. This indicates:
A. Chemical reaction
B. Physical change
C. No change
20. Which step is part of scientific experiments?
A. Guessing outcome
B. Careful observation and recording
C. Ignoring results