Class 6 chemistry important questions with answers are provided here for Chapter 15, Air Around Us. These important questions are based on the CBSE board curriculum and correspond to the most recent Class 6 chemistry syllabus. By practising these Class 6 important questions, students will be able to quickly review all of the ideas covered in the chapter and prepare for the Class 6 annual examinations.
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Class 6 Chapter 15 – Air Around Us Important Questions with Answers
Fill in the Blanks
i.) Plants absorb ____ to make their own food.
ii.) Oxygen is returned to the atmosphere by the process of ____.
iii.) Combustion cannot take place without ____ gas.
iv.) ____ gas maintains the temperature of the earth.
v.) Carbon dioxide is ____ than air.
Answer.
i.) Plants absorb carbon dioxide to make their own food.
ii.) Oxygen is returned to the atmosphere by the process of photosynthesis.
iii.) Combustion cannot take place without oxygen gas.
iv.) Carbon dioxide gas maintains the temperature of the earth.
v.) Carbon dioxide is heavier than air.
State True or False
i.) Plants use oxygen during photosynthesis.
ii.) The only elements in the air are nitrogen and oxygen.
iii.) Water vapour is present in the air.
iv.) Air exerts pressure.
v.) The composition of air is constant in the atmosphere.
Answer.
i.) True
ii.) False
iii.) True
iv.) True
v.) False
Match the Following
|
Column A |
Column B |
|
a.) Respiration |
i.) Process of preparing food by plants. |
|
b.) Air |
ii.) It is moving air. |
|
c.) Photosynthesis |
iii.) Process of burning food to get energy. |
|
d.) Nitrogen |
iv.) It is a gaseous mixture |
|
e.) Wind |
v.) The major component of air. |
Answer.
|
Column A |
Column B |
|
a.) Respiration |
iii.) Process of burning food to get energy. |
|
b.) Air |
iv.) It is a gaseous mixture |
|
c.) Photosynthesis |
i.) Process of preparing food by plants. |
|
d.) Nitrogen |
v.) The major component of air. |
|
e.) Wind |
ii.) It is moving air. |
Very Short Answer Questions
Q1. Name the main component of air.
Answer. Nitrogen.
Q2. What is the percentage of oxygen in the air?
Answer. 20.9%
Q3. What is the source of carbon dioxide in the atmosphere?
Answer. Animal and plant respiration, as well as fuel combustion.
Q4. Which gas in the air is necessary for combustion?
Answer. Oxygen.
Q5. Define humidity.
Answer. The amount of water vapour present in the air is humidity.
Q6. Which gas is given out during respiration by humans?
Answer. Carbon dioxide.
Q7. Can you see the air?
Answer. No, we cannot see air. We can only feel it.
Q8. Name some musical instruments in which air plays an important role.
Answer. Flute, saxophone, trumpet, horn, etc.
Q9. Which gas in the air is essential for breathing?
Answer. Oxygen.
Q10. Which gases in the air are not a supporter of combustion?
Answer. Nitrogen and carbon dioxide.
Short Answer Questions
Q1. Why is air considered a mixture?
Answer. Air is made up primarily of oxygen and nitrogen, as well as carbon dioxide and other gases. In the air, these gases retain their properties. As a result, the air is referred to as a mixture.
Q2. Why do you think mountaineers bring oxygen cylinders when climbing high mountains?
Answer. The amount of air decreases as we ascend higher into the atmosphere. The air at the summits of extremely high mountains is so thin that people cannot breathe properly. Mountaineers, or people who climb mountains, carry “oxygen gas” cylinders with them. They breathe in oxygen from these cylinders to survive on high mountains.
Q3. List the properties of air.
Answer. The following are the properties of air:
- It is colourless
- It is transparent
- It can be compressed.
- It occupies space
- It has mass
Q4. Define atmosphere.
Answer. The atmosphere is a gaseous blanket that surrounds the earth and contains the air we breathe. The planet’s gravitational attraction keeps it close to the planet’s surface.
Q5. Why do you feel suffocation in a closed room, where some material is burning?
Answer. In a closed room where some material is burning, we feel suffocated because the smoke contains few gases and harmful fine dust particles.
Q6. How does oxygen reach animals living in soil and water?
Answer. Air fills the space between the soil particles. The air between soil particles supplies oxygen to the animals that live there.
Aquatic animals and plants use dissolved oxygen in the water.
Q7. Why does the transparent glass of windows become hazy if it is not cleaned regularly?
Answer. Dust particles in the air adhere to the clear glass of windows. These particles also attract other elements, such as pollen, which collects on glass. As a result, if the windows’ transparent glass is not wiped regularly, it appears hazy.
Q8. What are the functions of long chimneys in factories?
Answer. When fuel is burned, smoke is produced. Frequent smoke is harmful because it contains a few gases and fine dust particles. Long chimneys in factories keep harmful gases and smoke away from the people living near the factory.
Q9. Why do our nostrils have fine hair and mucus? Why is it not recommended to breathe in through the mouth?
Answer. The air contains dust particles. Inside the nose, fine hair and mucus prevent dust particles from entering the respiratory system.
Dust particles may enter our respiratory tract if we breathe through our mouth because it lacks these dust barriers (fine hair and mucus). Hence, breathing through the mouth is not advised.
Q10. Why do animals that live deep in the soil come to the surface during heavy rains?
Answer. Animals that live in the soil obtain oxygen for breathing (or respiration) from the air that exists between the soil particles. When it rains heavily, water fills the spaces in the soil occupied by the air. In this situation, the animals living within the soil must emerge from the soil to breathe. Earthworms, for example, emerge from the soil only during heavy rains.
Long Answer Questions
Q1. Why do animals that live deep within the soil come to the surface during heavy rains? How can you say that animals and plants are mutually dependent?
Answer. Plants and animals are mutually dependent on survival. Plants cannot survive for long without animals because they require CO2 for photosynthesis, which is exhaled by animals. Similarly, animals will have no oxygen to breathe if plants do not exist. As a result, we can say that both are required to keep the balance of oxygen and carbon dioxide in the atmosphere.
Q2. Are breathing and respiration the same thing?
Answer. No, breathing and respiration are not the same things.
Breathing is a biophysical process in which oxygen is inhaled, and carbon dioxide is exhaled. In contrast, energy is produced during respiration by breaking down glucose, either in the presence of oxygen (aerobic respiration) or in the absence of oxygen (anaerobic respiration) (anaerobic respiration).
Thus, breathing is a physical process, whereas respiration is a chemical process.
Q3. Breathing through your mouth could be dangerous.” How?
Answer. The amount of dust particles in the air varies according to time and location. We inhale air when we breathe through our nostrils. Fine hair and mucus are found inside the nose to keep dust particles out of the respiratory system. Breathing through our mouths can be harmful because it allows dust from the air to enter our respiratory system (lungs, etc.) and harm our health.
Q4. How is oxygen replaced in the atmosphere or air?
Answer. The oxygen in the air is used by animals (and plants) through respiration and is constantly replaced by plants through photosynthesis.
Plants produce their own food while simultaneously producing oxygen. Plants also use oxygen for respiration, but they produce more than they consume. Because of this, plants are said to produce oxygen.
Animals cannot survive without plants. Similarly, plants cannot survive without animals. They would consume the entire amount of CO2 in the atmosphere. As a result, both are required to maintain the balance of oxygen and carbon dioxide in the atmosphere.
Q5. What will happen if atmospheric CO2 levels rise?
Answer. Carbon dioxide has the ability to absorb infrared rays, which are heat rays. Nature maintains a carbon dioxide balance in the atmosphere, which provides optimal warmth. Increased carbon dioxide concentration in the atmosphere would raise the earth’s temperature, causing glaciers to melt and flood, and so on. This is referred to as Global Warming.
Read Also:
- Air Around Us
- Components of Air
- Uses of Air
- Nitrogen
- Oxygen
- Carbon dioxide
- Class 6 Chemistry Worksheet Chapter 15 Air Around Us – Set 1
- Class 6 Chemistry Worksheet Chapter 15 Air Around Us – Set 2
- Class 6 Chemistry Worksheet Chapter 15 Air Around Us – Set 3
- Class 6 Chemistry Chapter 15 Air Around Us MCQs
- Air Pollution Questions
- Chemistry Concept Questions and Answers
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