1. Take an empty glass bottle. Turn it, upside down. Now, dip the open mouth of the bottle into the bucket filled with water. Now tilt the bottle slightly. You can see bubbles coming out of the bottle or hear any bubbly sound. Which of the following cannot be inferred from this activity?

2. Major part of the air is constituted by

3. Fix two small candles of the same size in the middle of two shallow containers. Now, fill the containers with some water. Light the candles and then cover each one of them with an inverted glass (one much taller than the other) Observe carefully what happens to the burning candles and the water level. What do you not infer from this experiment:

4. Mountaineers carry oxygen cylinders with them because

5. Which of the following gas helps in burning?

6. Mountaineers carry oxygen cylinder with them because:

7. What do plant and animal matter produce on burning ?

8. Which of the following gas we use in breathing?

9. Plants and animals consume oxygen for respiration and produce carbon dioxide. How is this carbon dioxide consumed to balance the carbon dioxide—oxygen balance.

10. Which of the following gas helps in burning?

11. Wind is

12. We should breathe through the nose and not by the mouth, because ____

13. Which of the following plays a very important role in the oxygen cycle?

14. Air is present in

15. Take some water in a glass vessel or beaker. Heat it slowly on a tripod stand. Well before the water begins to boil, look carefully at the inner surface of the vessel. From where do these bubbles come?

16. What do plant animal matter consume on burning ?

17. Air is

18. Earth worms come out of the soil during rainy seasons because:

19. Which of the following gas we use in breathing?

20. Envelope of air that surrounds the earth is known as

21.  

This is a wind mill. It uses air for:

22. The balance between carbon dioxide and oxygen is maintained by

23. Which is not a property of air?

24. Air plays an important role in water cycle. How?

25. contains few gases and fire dust particle.

26. The ratio of nitrogen to oxygen in the air is

27. Plants depend on animals and animals depend on plants. How?

28. Wind is

29. The main constituent of the air is.

30. Air is a/an

31. The layer of air around the earth surface is called

32. Which of the following component of air cannot be taken directly by plants?

33. Mountaineers carry cylinders with them.

34. Wind mill is used

35. Air is present in

36. In which of the following cities would there be maximum water vapour in the air on a sunny day in December?

37. The active part of air is

38. If burning splinter is taken close to the gas jar filled with oxygen, taken gas formed is

39. The properties of air are:

40. The components of air which are harmful to living beings are

41. Oxygen is consumed from atmosphere in the following process

42. The percentage composition of oxygen in air is

43. When the bottle was tilted, the air was able to come out in the form of.

44. Nitrogen is used

45. Envelope of air that surrounds the earth is known as

46. Which gas makes up major part of the air?

47. Which of the following processes need oxygen?

48. The constituent of air that supports combustion is

49. Which of the following is a variable component of air ?

50. The atmospheric layer nearest the earth's surface is the

51. Which of the following is second layer of atmosphere?