About one fifth of ordinary air is

1

(a)

nitrogen

(b)

carbon dioxide

(c)

water vapour

(d)

oxygen

Which of the following components of air is present in the largest amount in the atmosphere?

1

(a)

Nitrogen

(b)

Oxygen

(c)

Water vapour

(d)

Carbon dioxide

Wind does not help in the movement of which of the following?

1

(a)

Firki

(b)

Weather cock

(c)

ceiling fan

(d)

Sailing yacht

Which of the following statements is incorrect?

1

(a)

All living things require air to breathe

(b)

We can feel air but we cannot see it

(c)

Moving air makes it possible to fly a kite

(d)

Air is present everywhere but not in soil

CNG means:

1

(a)

Common Natural Gas

(b)

Compressed Natural Gas

(c)

Common Natural Gasoline

(d)

Compressed Natural Gasoline

The component of air used by green plants to make their food is _________

1

(a)

carbon dioxide

The _________ particles can be seen moving in a beam of sunlight in a dark room.

1

(a)

dust

Aquatic animals use dissolved ________ in water for respiration

1

(a)

oxygen

Air helps in the dispersal of ____ and _______ of flowers of several plants.

1

(a)

seeds, pollen

Mountaineers carry oxygen ___________ with them, while climbing high mountains.

1

(a)

cylinders

The composition of air is always exactly the same

1

(a) True

(b) False

Atmosphere is essential for life on the earth.

1

(a) False

(b) True

Air is a mixture of many gases.

1

(a) False

(b) True

Green plants need carbon dioxide gas to make food

1

(a) False

(b) True

Respiration can occur only in the presence of nitrogen

1

(a) True

(b) False

Name the major part of air that does not support burning.

2

(a)

Policemen use the masks for what reason?

2

(a)

Have you ever seen air ?

2

(a)

How will you prove that air supports burning?

2

(a)

Why do you think mountaineers carry oxygen cylinders with them, while climbing high mountains?

2

(a)

What is the composition of air?

3

(a)

How will you show that air is dissolved in water?

3

(a)

List five activities that are possible due to the presence of air

3

(a)

When an empty glass bottle is inverted and inserted into a trough filled with water, water does not enter the bottle. Specify.

3

(a)

Air takes the shape, smell, etc from the object/ place it is present in. Explain.

3

(a)

Humans and animals use oxygen for respiration and plants require carbon dioxide for photosynthesis. How are these two processes related?

5

(a)

Air present in atmosphere will be defined as what? Name the major constituents of air. Give their volume proportions in air.

5

(a)