Air and Its Composition

Q.

What are the different types of gases present in air and what is the percentage of the different gases which are present?

Q.

Why do mountaineers carry oxygen cylinders with them?

Q.

What do we get from plants?

Q. The air density ___ with the increase in altitude.

1. increases
2. decreases
3. remains the same
4. changes unpredictably

Q.

Which of the following enables us to drink a liquid through a straw?

1. Diffusion

2. Humidity

3. Atmospheric pressure

4. Temperature

Q.

How do plants benefit humans?

Q. Density of air____________ with height.

1. increases
2. decreases
3. first increases then decreases
4. remains same

Q.

Soil contains small amounts of air in it.

1. False

2. True

Q. Will the tiny air bubbles seen before the water actually boils, also appear if we do the boiling water in a vessel activity by reheating boil water kept in an air tight bottle?

Q.

The air we breathe out is rich in oxygen and moisture.

1. True
2. False

Q.

What conditions do we need to see dust particles in the air?

1. A bright narrow beam of light in a dark room

2. A bright beam of light in daylight

3. Dust particles in the air cannot be seen under any condition

4. A beam of laser light in daylight

Q.

What is the role of the atmosphere in climate control?

Q. Why are the objects at a distance seen more clearly after rains?

Q. Which property of air allows us to see each other?

1. It has mass.
2. It occupies space.
3. It is transparent.
4. It is odourless.

Q. The most abundant component of air is .

1. oxygen
2. nitrogen
3. water vapour

Q. Arrange the following in the decreasing order of their composition in the atmosphere.

1. Nitrogen
2. Oxygen
3. Argon
4. Carbon dioxide

Q.

Which gas is required for burning fuel?

1. Nitrogen

2. Carbon dioxide

3. Oxygen

4. (a), (b) and (c)

Q.

What would happened if there would have been no atmosphere around the earth?

Q.

The constituent of air that takes part in photosynthesis is …………

Q. Which of the following is/are present in air?

1. Oxygen
2. Water vapour
3. Carbon dioxide
4. Nitrogen

Q.

Clouds are formed from tiny droplets of water vapour.

1. Atmospheric pressure decreases with increase in depth.

2. Atmospheric pressure decreases with increase in height.

Q.

The atmosphere around the Earth acts like a blanket and controls the temperature. During the daytime, it prevents the sudden rise of temperature and during the night, it prevents the heat from escaping away to the atmosphere.

1. False

2. True

Q.

What are the roles played by the atmosphere in climate control?

Q. Write just a few sentences for an imaginary situation if any of the following gases disappear from the atmosphere.​
(a) oxygen​
(b) nitrogen
(c) carbon dioxide

Q.

What is not true about the air?

1. It makes the windmill rotate.

2. It helps in the movements of aero planes.

3. Birds can fly due to the presence of air.

4. It has no role in the water cycle.

Q.

Which of the following properties of air is/are not true?

1. Air has mass and occupies space.

2. Air can be easily compressed.

3. Air exerts pressure in all directions but unequally.

4. Air is a mixture of gases.

Q.

The water droplets formed around a glass containing ice comes from

1. the ice itself

2. the water inside the glass

3. the atmosphere

4. the reaction of glass with coldness

Q.

The solid particle which imbibes is called ……… while the liquid which imbibed is called …….

Q.

26. Calculate the volume of nitrogen, oxygen and carbon dioxide in 750 L of air.

Q. An empty glass turned upside down is actually not empty. It is full of _____.

1. water
2. air
3. water vapour
4. carbon dioxide gas