Important Questions Class 6 Science Chapter 15

Important Questions Class 6 Science Chapter 15 – Air Around Us

Studying Science is a very demanding concept requiring students to follow through thoroughly at every step. For a good exam score, students must understand the theory and its working principles.Understanding concepts alone is not sufficient.They must practise questions regularly to improve their theoretical and practical application of learned concepts.

Chapter 15 of Science Class 6 deals with the air present around us. It introduces students to various topics, which are given below as stated:

• Presence of air
• Composition of air
• Oxygen’s importance
• Oxygen cycle

This chapter is essential for students as it teaches them about the basic need for survival: air. For decades, the air was not studied. However,  time and research efforts proved that air is a mixture of a lot of gases like water vapour, oxygen, carbon dioxide, nitrogen, and pollutants like smoke and dust. Scientists have revealed more details about the atmosphere and air as science and technology progressed.Most of the advanced topics will be discussed in higher classes.

For overall preparation for exams, students must solve questions regularly and as much as possible. Extramarks, an educational platform that provides study materials for exams, provides question banks like Important Questions Class 6 Science Chapter 15 to help students practise and overcome their fear of exams. Furthermore, students are advised to solve Chapter 15 Class 6 Science Important Questions for a better understanding of concepts.

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Important Questions Class 6 Science Chapter 15 – With Solutions

Solving Important Questions Class 6 Science Chapter 15 helps students in revising important concepts and retaining all the important sections of the chapter. Important Questions Class 6 Science Chapter 15

Extramarks question bank are curated by subject experts.

Solving Class 6 Science Chapter 15 Important Questions prior to exams will help students review the entire chapter in one sitting.Given below is a list of all the Important Questions Chapter 15, Class 6

Question 1: What is the composition of air?

Answer 1: Atmospheric air comprises oxygen(21%), nitrogen(78%), carbon dioxide, water vapour and pollutants(1%) like dust and smoke.

Question 2: Why does a lump of cotton wool shrink in water?

Answer 2: A lump of cotton wool shrinks in water as air pockets are present in the cotton. When it is dipped in water, air pockets are replaced with water, making the cotton fabric stick together. This causes the cotton wool lump to shrink in water.

Question 3: Which are the five processes that require the presence of air?

Answer 3: Processes which require the presence of air are:

1. Cloud formation
2. Respiration
3. Transpiration
4. Winnowing
5. Photosynthesis

Question 4: How do plants and animals help each other in the exchange of gases in the atmosphere?

Answer 4: Two processes, respiration and photosynthesis, help plants and animals exchange the gases in the atmosphere. In respiration, plants and animals take in oxygen and give out carbon oxide.

Plants, during the day, take in carbon dioxide and synthesise food, giving out oxygen into the atmosphere as a byproduct. Thus, plants and animals help each other in the exchange of gases and maintain the balance of gases in the atmosphere.

Question 5: The blanket of air surrounding the earth is known as ________.

Answer 5: The blanket of air surrounding the earth is known as the atmosphere.

Question 6: The component of air used to make food by green plants is ___________.

Answer 6: The component of air used to make food by green plants is carbon dioxide.

Question 7: Solve the following multiple-choice questions given below.

(i) Wind does not help in the movement of which of the following?

(a)Weathercock

(b) Sailing yacht

(c) Ceiling fan

(d) Firki

Answer (i): ( c) Ceiling fan

A ceiling fan runs on electricity; hence, wind doesn’t help in the movement of the fan.

(ii)  What is not true about the air?

(a) It helps in the movements of aeroplanes.

(b) Birds can fly due to the presence of air.

(c)It makes the windmill rotate.

(d) It has no role in the water cycle.

Answer (ii): (d) It has no role in the water cycle.

Air plays the biggest role in the water cycle as water vapours rise to form clouds.

(iii) Why do mountaineers need to carry oxygen cylinders with them? Because

(a) there is no oxygen in high mountains

(b) there is a lot of deficiency of oxygen in the mountains at high altitudes

(c) oxygen keeps them warm at low temperatures.

(d) oxygen is used for cooking

Answer (iii): (b) there is a lot of deficiency of oxygen in the mountains at high altitudes.

Mountaineers carry oxygen cylinders with them because there is a deficiency of oxygen in the mountains at high altitudes. As we go higher in altitude, the atmosphere gets thinner, and the oxygen supply decreases. Therefore while climbing mountains, it makes breathing difficult. Hence, mountaineers carry oxygen cylinders with them.

(iv) In our atmosphere, which components of the air are present in the largest amount?

(a) Nitrogen

(b) Water vapour

(c) Oxygen

(d) Carbon dioxide

Answer (iv): (a) Nitrogen

The atmosphere is composed of so many different gases, but the gas present in the largest amount is nitrogen, which is 78%.  Other gases found in the atmosphere include oxygen (21%), and carbon dioxide (1%).

(v)Anya took a lump of dry soil in a glass beaker and added water to it  until the soil was completely immersed. She observed bubbles coming out of the soil. The bubbles contain

(a) only oxygen gas

(b) water vapour

(c) air

(d) none of these.

Answer (v): (c ) air

When water is poured into dry soil, the soil absorbs the water, and the air pockets present in the soil escape and form bubbles.

Question 7: Explain the reasons for the following statements:

(a) A firki does not rotate in a closed area.

(b) The arrow of the weathercock points towards a particular direction at a particular moment.

(c) An empty glass, in fact, is not empty.

(d) Breathing through the mouth may harm you.

Answer 7: 

1. There is a lack of air movement in a closed area, which prevents firki rotation. Because of the moving air all around, a firki usually rotates when placed in an open area.
2. A weathercock is a device that indicates the direction of the wind. It is made up of an arrow that is mounted at its centre of gravity and can freely rotate around a vertical axis. As a result, the arrow points in a specific direction at a specific time to indicate the most recent direction of the wind’s movement.
3. An empty glass is not empty; it contains air. It can be demonstrated by using a simple experiment. Place an empty bottle upside down in a beaker that is filled with water. Water does not enter the bottle when pushed inverted because there is no space for the air to escape.When the bottle is tilted, the air escapes as bubbles, and the empty space is filled with water. This demonstrates that even an empty glass contains air.
4. Yes, breathing through our mouths can be harmful. The air may contain gases, water vapour, and dust particles. When we breathe in through our nostrils, the fine hair and mucus in our nose keep dust particles from entering our respiratory tract. However, if we breathe through our mouths, harmful dust particles may enter our bodies and make us sick. As a result, breathing through the mouth may be harmful.

Question 8: Explain why burning a fire in an enclosed room causes people to suffocate.

Answer 8: Any burning substance requires oxygen to burn and releases carbon dioxide. In a closed room, there is limited oxygen supply, and the carbon dioxide released cannot be accumulated nor expelled.As a result, in a closed room with fire, humans have less oxygen to breathe and later start inhaling the carbon dioxide released. Carbon dioxide is harmful to humans as it combines with haemoglobin present in the blood faster than oxygen. Resulting in asphyxia which proves to be fatal.

Question 9: Why should we breathe through our nose and not our mouth?

Answer 9: The human nose has two nostrils, each coated with a dense layer of tiny nostrils and a thick layer of mucus. The tiny hairs act as filters, removing smoke particles and dust, allowing air free of dangerous airborne particles to enter our respiratory system. As our mouth lacks all these filters, it is not advised to breathe through the mouth.

Question 10: State whether the following statements are true or false.

1. Air is always stationary. 

Answer: False. 

Air can flow, and flowing air is called wind.

1. Air is present everywhere.

Answer: True.

1. Air occupies space. 

Answer: True.

1. Air is coloured. 

Answer: False.

Air is transparent, colourless, and odourless.

1. The layer of air surrounding the earth is called oxygen. 

Answer: False.

The layer of air surrounding the earth like a blanket is called the atmosphere.

1. Nitrogen does not support burning. 

Answer: True.

1. Plants use oxygen for respiration and carbon dioxide for photosynthesis.

Answer: True.

1. Dust particles are present in the air. 

Answer: True.

1. Oxygen cannot be dissolved in water.

Answer: False.

Oxygen can be dissolved in water.

1. Windmills require electricity to function.

Answer: False.

Windmills generate electricity by harnessing the power of the wind.

Benefits of Solving Important Questions Class 6 Science Chapter 15

Important Questions Class 6 Science Chapter 15 is specially designed by professionals at Extramarks. It helps students score well in exams by giving them an extra edge in writing answers. This question bank is prepared by experts and includes important questions with a higher likelihood of appearing in exams. Hence, students are advised to solve Important Questions Class 6 Science Chapter 15 before appearing in exams.

Listed below are a few benefits of solving Important Questions Class 6 Science Chapter 15:

1.  Important Questions Class 6 Science Chapter 15 contains questions from the NCERT textbook, NCERT Exemplars, and references. It also consists of all formats of questions, like Multiple Choice Questions [MCQs], very short answers, short answer type, and long answer type questions.
2. By solving such questions regularly, students get practice for real exams. Hence, it helps students to score good marks in exams as it helps in understanding the concept and improving the application of the concept.
3. The question bank Important Questions Class 6 Science Chapter 15 not only is a combination of all the important questions but also includes a detailed step-by-step solution to each question, which aids in students’ preparation for exams.’
4. Important Questions, Class 6 Science Chapter 15, aids in students’ self-evaluation by highlighting weak areas of the student or topics that were missed by the student.By solving Important Questions Class 6 Science Chapter 15, students get ample time to recognise and work on their weak points.

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