ICSE Class 6 Chemistry - Air and Atmosphere - Test 4 (Expert)
1. Two burning candles are covered with glass jars of different sizes. The candle under the smaller jar goes out first because:
A. The small jar has more oxygen
B. The small jar has less oxygen
C. The candle changes into water
2. A burning candle is placed in a dish of water and covered with a jar. The water level rises inside the jar because:
A. Water starts burning
B. Nitrogen changes into liquid
C. Some oxygen is used up
3. When we blow air through lime water, it turns milky. This shows that exhaled air contains more:
A. Carbon dioxide
B. Oxygen
C. Nitrogen only
4. A mirror becomes misty when we breathe on it. This shows that our breath contains:
A. Sand
B. Water vapour
C. Iron dust
5. A cyclist finds it harder to ride against strong wind because air:
A. Has no effect on motion
B. Becomes a solid wall
C. Offers resistance
6. A paper pinwheel rotates when air blows on it. This shows that moving air can:
A. Do work by pushing objects
B. Remove all oxygen
C. Become invisible water
7. Thick smoke from burning coal makes nearby air harmful because it contains:
A. Only clean oxygen
B. Harmful gases and particles
C. Pure water only
8. A park with many trees usually has fresher air because trees:
A. Produce smoke
B. Remove all nitrogen
C. Use carbon dioxide and release oxygen
9. When the nozzle of an air-filled syringe is closed and the plunger is pushed, the air gets compressed. This shows that air:
A. Can be compressed
B. Has fixed shape
C. Is a liquid
10. A sheet of paper is pressed against the mouth of an empty glass and the glass is turned upside down. The paper may stay for a short time mainly because of:
A. Fire
B. Air pressure
C. Dust only
11. Smoke from a fire usually rises upward because warm air:
A. Becomes a solid
B. Stops moving
C. Rises upward
12. A factory chimney releasing dark smoke is likely to cause:
A. Air pollution
B. Pure oxygen formation only
C. Clean rainwater only
13. A person covers the nose with a mask on a dusty road mainly to avoid breathing in:
A. Clean air
B. Dust particles
C. Pure nitrogen crystals
14. Carbon dioxide from a fire extinguisher is useful because it:
A. Gives more oxygen to fire
B. Burns faster than wood
C. Cuts off the support for burning
15. During breathing, humans take in oxygen and give out more:
A. Carbon dioxide
B. Gold dust
C. Pure hydrogen
16. If Earth had no atmosphere, living beings would not survive easily because there would be no:
A. Rocks
B. Air for breathing
C. Soil at all
17. Clouds are formed when water vapour in air cools and changes into tiny:
A. Stones
B. Flames
C. Water droplets
18. Which action is best for reducing air pollution near a school?
A. Avoiding burning waste
B. Burning plastic daily
C. Cutting all plants
19. We can hear a bell ringing in a classroom because air helps carry:
A. Shadows
B. Sound
C. Solid stones
20. Which statement best explains why air is important?
A. Air is useful only for flying kites
B. Air contains only one gas
C. Air supports life and many natural processes