Air

Q.

Write $5$ things which dissolve in Water and Which do not dissolve in Water.

Q.

Why is carbon dioxide a non-polar molecule, even though the C-O bonds are polar?

Q. Gentle and moderate wind is called _____.

1. breeze
2. thunder
3. gust
4. storm

Q. Why do earthworm come out during heavy rainfall

Q.

Why the air is transparent?

Q.

To expel hot air out of the kitchen, ‘A’ has an exhaust fan fitted on the window of her kitchen, and ‘B’ has a similar exhaust fan fitted on the wall near the ceiling of her kitchen. Which of the exhaust fan will expel the hot air more effectively? Explain why?

Q. Out of the following, which gas is not present in the air in abundance?

1. Nitrogen
2. Oxygen
3. Hydrogen
4. Water vapour

Q. Photosynthesis is a process by which green plants ________.

1. absorb oxygen
2. prepare food
3. generate new plants
4. release carbon dioxide

Q. Which gas constitutes nearly 21% of air by volume?

1. Oxygen
2. Nitrogen
3. Hydrogen
4. Argon

Q.

Carbon dioxide is present to the extent of only 0.03 % in air, yet it is very important for plants. Why ?

Q.

Moving blades of a windmill have _________ (rotatory/ curvilinear) motion.

Q. Why is the atmosphere essential for life?

1. It acts as a blanket and keeps the average temperature of the Earth
2. It contains all the gases which are essential for sustaining life on the Earth
3. Ozone layer present in the atmosphere prevents harmful UV rays from reaching the Earth
4. Water cycle is not possible without atmosphere

Q. Which of the following animals use dissolved oxygen in water for respiration?

1. Rat
2. Fish
3. Prawn
4. Earthworm

Q. Which of the following is true about air?

1. Air is a mixture of several gases.
2. Air exerts pressure.
3. Composition of air is uniform.
4. Air has mass.

Q. Air is present in gaseous state.

1. True
2. False

Q. State True or False:
The atmosphere acts like a blanket and helps in controlling the climate. During the day time, it prevents the sudden rise of temperature and during the night, it prevents heat from escaping to outer space.

1. True
2. False

Q.

Air doesn't support burning.

1. True

2. False

Q. Select the correct statements about uses of air?

1. It makes windmills rotate.
2. It helps in cooking.
3. It helps in paragliding.
4. It makes pinwheel spin.

Q.

Read the two statements and choose the correct option.
(i) The compressed air in a tyre exerts a force enough to lift a heavy car.
(ii) In a syringe, the plunger compresses the liquid.

1. Both the statements are true.

2. Both the statements are false.

3. Statement (i) is true but statement (ii) is false.

4. Statement (i) is false but statement (ii) is true.

Q.

Varun went on an educational trip to Gujarat. He made a diary entry of his visit and enlisted a lot of things he saw during his visit. He is making a list of things which require air as an important component for functioning but he is not sure. Help him to make the list of activities where air plays a major role in functioning. The list is as follows:

1)Varun visited a windmill power plant and observed how power is generated.

2)He visited many monuments including Gandhi Ashram.

3)He participated in a kite flying competition.

4)He started reading a new book on "Atmosphere”.

5)He did sky diving where he jumped from a great height and landed on the ground through a parachute.

6) He and his team mates did a camp fire.

Q.

Air is present all around us but still we do not see it. Why ?

Q. Choose the organisms which take in oxygen from soil.

1. Rat
2. Snake
3. Earthworm
4. Fish

Q. Why does the oxygen in the atmosphere never get exhausted despite the growing population?

1. Once oxygen is exhausted, we can breathe other gases.
2. We can live without oxygen.
3. Oxygen consumed by humans are balanced by photosynthesis of plants.
4. Earth's atmosphere has a large reservoir of oxygen.

Q.

What happens during the development of thunderstorms?

1. Air current moves downwards, water droplets move downwards

2. Air current moves downwards, water droplets move upwards

3. Air current moves upwards, water droplets move downwards

4. Air current moves upwards, water droplets move upwards

Q.

Earthworms go deep inside the soil after a heavy rainfall.

1. True
2. False

Q.

What is the percentage of oxygen in the atmosphere?

1. 78%
2. 21%
3. 12%
4. 11%

Q.

Which of the following is necessary for photosynthesis?

1. Carbon dioxide

2. Methane

3. Nitrogen

4. Oxygen

Q.

Name the process by which plants prepare their own food.

Q. Aquatic animals use dissolved in water for respiration.

1. oxygen
2. nitrogen
3. carbon dioxide

Q.

Which of the following is caused due to the formation of high and low pressure belts in the atmosphere?

1. hurricane

2. typhoon

3. tornado

4. thunderstorm