Page 1 - CBW

SAI International School

Competency Based Worksheet
Subject – Chemistry

Chapter – Air Around Us

Class- VI

Q. No. Questions

1. A candle placed in a closed jar stops burning after some time. What does this experiment
prove?
a. The jar breaks
b. Candle needs wax
c. Candle needs oxygen to burn
d. Candle cools down

2. Which of the following best explains the presence of dust particles in air?
a. Air is always clean
b. Dust is a part of soil
c. Air is a mixture and carries suspended particles
d. Dust is produced by fire
3. Why do mountaineers carry oxygen cylinders with them?
a. To breathe easier at high altitudes
b. To keep warm
c. To cook food faster
d. To avoid sunburn

4. Which of the following is not a component of air?
a. Water vapour
b. Oxygen
c. Helium
d. Smoke

5. How can you show that air supports burning?
a. Burn a candle in water
b. Burn a candle in a closed jar and observe when it stops
c. Burn a wet matchstick
d. Blow air from your mouth

Choose the correct option for the following: (For questions- 6 and 7)
a) If both Assertion and Reason are correct and Reason is the correct explanation of
Assertion.
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of
Assertion.
c) If Assertion is correct but Reason is incorrect.

d) If assertion is incorrect but Reason is correct.
e) If Assertion and Reason both are incorrect.