Nature’s Treasures – Important Questions and Answers
Premium CBSE Class 6 Science revision post based on the chapter Nature’s Treasures. Includes air, oxygen, wind, water, freshwater conservation, rainwater harvesting, solar energy, forests, soil, rocks, minerals, fossil fuels, renewable and non-renewable resources, human-made resources, case studies, HOTS questions, diagram-based questions, FAQs, and an interactive quiz.
Short Introduction
Nature provides many treasures that make life possible on Earth. Air gives us oxygen for breathing, water supports life and daily activities, sunlight gives heat and light, forests provide food and shelter, soil supports plant growth, rocks and minerals help us make useful things, and fossil fuels provide energy. This chapter teaches students that natural resources are precious and must be used carefully, conserved properly and protected from pollution.
Chapter Overview
Air
Air contains nitrogen, oxygen, argon, carbon dioxide and other gases. Oxygen is essential for survival.
Wind
Moving air is called wind. Wind can rotate a firki and windmills can use wind energy to generate electricity.
Water
Water is used for drinking, cooking, bathing, washing, cleaning, agriculture and industry. Freshwater is limited.
Sun
The Sun is the main source of energy on Earth. It gives heat and light and helps plants prepare food.
Forests
Forests are large areas with dense growth of plants. They provide food, shelter and support biodiversity.
Soil, Rocks and Minerals
Soil supports plant growth, while rocks and minerals are used for construction, tools, metals and many products.
Fossil Fuels
Coal, petroleum and natural gas are fossil fuels. They take millions of years to form and are limited.
Resources
Natural resources can be renewable or non-renewable. They should be used judiciously.
Important Concept Flow
Air is a mixture of gases surrounding Earth.
Wind energy can be used to run flour mills, pull water from wells and generate electricity.
Most water is saline; only a small fraction of freshwater is easily accessible.
The Sun is the main source of energy for life on Earth.
Soil forms by the breaking apart of rocks over thousands of years.
Fossil fuels are non-renewable and cause pollution when burnt.
Important Keywords with Meanings
| Keyword | Meaning |
|---|---|
| Natural resources | Resources that we get from nature, such as air, water, sunlight, forests, soil, rocks and minerals. |
| Human-made resources | Resources created by human beings to meet their needs, such as furniture, bicycles, electric bulbs and solar panels. |
| Air | A mixture of gases surrounding Earth. |
| Oxygen | A gas present in air that most living beings need for survival. |
| Nitrogen | The gas present in the largest amount in air, about 78%. |
| Carbon dioxide | A gas present in small quantity in air. |
| Wind | Moving air. |
| Breeze | Gentle moving air. |
| Storm | Very fast-moving air. |
| Windmill | A device whose wings rotate due to wind and can be used to generate electricity or pull water. |
| Water | A natural resource needed for drinking, cooking, bathing, washing, agriculture and industry. |
| Freshwater | Water fit for domestic, agricultural and industrial use. |
| Saline water | Salty water found mainly in oceans and seas. |
| Water conservation | Saving water and using it carefully without wastage. |
| Rainwater harvesting | Collecting and storing rainwater for later use. |
| Bawadi / Vav | Traditional stepwells used for water harvesting in Rajasthan and Gujarat. |
| Solar energy | Energy obtained from the Sun. |
| Solar panel | A device that captures Sun’s energy and produces electricity. |
| Solar cooker | A device that uses solar energy for cooking food. |
| Solar water heater | A device that uses solar energy to heat water. |
| Forest | A large area with dense growth of various types of plants. |
| Biodiversity | The variety of living beings in an area. |
| Van Mahotsav | A week-long forest festival celebrated in July to plant trees and spread awareness. |
| Chipko movement | A movement in which people hugged trees to protect them from being cut. |
| Soil | The upper layer of Earth that supports plant growth. |
| Rock | A hard natural material used for construction and other purposes. |
| Minerals | Substances present in rocks from which metals and useful materials are obtained. |
| Fossil fuels | Fuels formed from remains of ancient microorganisms and plants; examples are coal, petroleum and natural gas. |
| Petroleum | A fossil fuel from which petrol, diesel and kerosene are obtained. |
| Coal | A fossil fuel mainly used for producing electricity. |
| Natural gas | A fossil fuel used for cooking, generating electricity and as CNG in vehicles. |
| CNG | Compressed Natural Gas, used as a cleaner vehicle fuel than petrol or diesel. |
| Renewable resources | Resources that are renewed, replenished or restored by nature within a reasonable time. |
| Non-renewable resources | Resources available in limited quantities that do not get replenished within a reasonable time. |
Very Short Answer Questions
1. What are nature’s treasures?
Answer: Nature’s treasures are natural resources such as air, water, sunlight, forests, soil, rocks, minerals and fossil fuels.
2. Why do we need oxygen?
Answer: We need oxygen for survival and for our body to perform its functions.
3. What is air?
Answer: Air is a mixture of gases surrounding Earth.
4. Which gas is present in the largest amount in air?
Answer: Nitrogen.
5. What percentage of air is oxygen?
Answer: Oxygen makes up about 21% of air.
6. What percentage of air is nitrogen?
Answer: Nitrogen makes up about 78% of air.
7. What is moving air called?
Answer: Moving air is called wind.
8. What is a breeze?
Answer: A gentle wind is called a breeze.
9. What makes a firki rotate?
Answer: Wind makes a firki rotate.
10. Name one use of a windmill.
Answer: A windmill can be used to generate electricity.
11. Name two daily uses of water.
Answer: Drinking and cooking.
12. Why is ocean water not fit for drinking?
Answer: Ocean water is saline or salty.
13. What is rainwater harvesting?
Answer: Rainwater harvesting is the collection and storage of rainwater for later use.
14. What is Bawadi?
Answer: Bawadi is a traditional stepwell used for water harvesting in Rajasthan.
15. Which is the main source of energy on Earth?
Answer: The Sun is the main source of energy on Earth.
16. What do solar panels do?
Answer: Solar panels capture energy from the Sun and produce electricity.
17. What are forests?
Answer: Forests are large areas with dense growth of various types of plants.
18. What is Van Mahotsav?
Answer: Van Mahotsav is a week-long forest festival celebrated in July to plant trees and spread awareness.
19. What is soil formed from?
Answer: Soil is formed by the breaking apart of rocks over a long time.
20. Name one natural agent that helps loosen soil.
Answer: Earthworms help loosen soil.
21. What are fossil fuels?
Answer: Fossil fuels are fuels formed from remains of microorganisms and plants buried deep inside Earth.
22. Name three fossil fuels.
Answer: Coal, petroleum and natural gas.
23. From which fossil fuel are petrol and diesel obtained?
Answer: Petrol and diesel are obtained from petroleum.
24. Give one example of a renewable resource.
Answer: Air.
25. Give one example of a non-renewable resource.
Answer: Coal.
Short Answer Questions
1. Why are natural resources called nature’s treasures?
Answer: Natural resources are called nature’s treasures because they are provided by nature and are essential for life. Air, water, sunlight, forests, soil, rocks, minerals and fossil fuels support survival and make life comfortable.
2. Why can we not hold our breath for a long time?
Answer: We cannot hold our breath for a long time because our body needs oxygen to perform its functions. When we hold our breath, the body does not get enough oxygen.
3. Write the composition of air.
Answer: Air contains about 78% nitrogen, 21% oxygen and 1% argon, carbon dioxide and other gases.
4. What is wind? Give two examples where we notice wind.
Answer: Moving air is called wind. We notice wind when leaves rustle, clothes sway on a clothesline, or pages of a book flutter when a fan is switched on.
5. How are windmills useful?
Answer: Windmills use wind energy. They can run flour mills, pull water from wells and generate electricity.
6. Why is water called precious?
Answer: Water is precious because we need it for drinking, cooking, bathing, washing, cleaning, farming and industry. Although Earth has a lot of water, only a small fraction of freshwater is easily accessible.
7. Why is most water on Earth not directly usable?
Answer: Most water on Earth is found in oceans and seas and is saline. Saline water is not fit for domestic, agricultural and industrial use.
8. Write two ways to reduce water wastage.
Answer: Water wastage can be reduced by turning off taps when not in use and fixing water leakages.
9. How do humans pollute freshwater sources?
Answer: Humans pollute freshwater sources by throwing plastic bags, wrappers, household waste and industrial waste into rivers, lakes and ponds.
10. Why is the Sun important for life on Earth?
Answer: The Sun provides heat and light. Plants use sunlight to prepare food. Animals and humans depend on plants directly or indirectly for food, so the Sun is the main source of energy.
11. Write two uses of solar energy.
Answer: Solar energy can be used to generate electricity using solar panels and to cook food using a solar cooker.
12. Why are forests important?
Answer: Forests provide food and shelter to animals, birds and insects. They support biodiversity, protect soil and provide many useful products.
13. How do roots of plants help soil?
Answer: Roots hold the soil and prevent it from being washed away. They also help keep the soil stable.
14. How do fallen leaves help the soil?
Answer: Fallen leaves decay and enrich the soil with nutrients. This is an example of recycling in nature.
15. Why are fossil fuels non-renewable?
Answer: Fossil fuels take millions of years to form and are found in limited quantities. They do not get replenished within a reasonable period of time.
Long Answer Questions
1. Explain why air is an important natural resource.
Answer: Air is essential for life. It contains oxygen, which most living beings need for survival. Humans and animals breathe in oxygen to perform body functions. Plants also need air for life processes. Air is a mixture of gases, mainly nitrogen, oxygen, argon, carbon dioxide and other gases. Moving air, called wind, is also useful because it can rotate windmills and help generate electricity. Thus, air is an important natural resource.
2. Describe the composition of air with percentage.
Answer: Air is a mixture of gases. Out of 100 parts of air:
- 78 parts are nitrogen.
- 21 parts are oxygen.
- 1 part consists of argon, carbon dioxide and other gases.
Oxygen is essential for breathing, while nitrogen is present in the largest amount.
3. Explain the importance and uses of water.
Answer: Water is essential for all living beings. We use water for drinking, cooking, bathing, washing, cleaning and gardening. Farmers need water for growing crops. Industries also use water for different processes. Animals need water for drinking, and plants need water for growth. Since only a small fraction of freshwater is easily accessible, water should be used carefully and not wasted.
4. Why should we conserve water? Write some methods of water conservation.
Answer: We should conserve water because freshwater is limited and many people face water shortage. Water can be conserved by:
- Turning off taps when not in use.
- Fixing leaking taps and pipes.
- Using buckets instead of showers where possible.
- Recycling water for gardening or cleaning.
- Practising rainwater harvesting.
- Preventing pollution of rivers, lakes and ponds.
5. Explain rainwater harvesting and traditional stepwells.
Answer: Rainwater harvesting is the method of collecting and storing rainwater for later use. In many buildings, rainwater is collected and stored in large quantities. It is an age-old practice in India. Traditional stepwells, called Bawadi in Rajasthan and Vav in Gujarat, were built to store rainwater and water seeping from nearby lakes, ponds and rivers. They helped people deal with scarcity of water.
6. Explain why the Sun is called the main source of energy on Earth.
Answer: The Sun gives heat and light to Earth. Plants use sunlight to prepare food. Animals eat plants or other animals and get energy. Humans also depend on plants and animals for food. Solar energy is also used directly in solar panels, solar cookers and solar water heaters. Therefore, almost all living beings depend on the Sun directly or indirectly, making it the main source of energy on Earth.
7. Explain the importance of forests.
Answer: Forests are large areas with dense growth of plants. They are natural homes for many wild animals, birds and insects. Forests provide food and shelter, support biodiversity, help protect soil, and provide useful products such as fruits, wood, medicinal plants and fibres. Forests take many years to grow, so they must be preserved and used responsibly.
8. How is soil formed and why is it important?
Answer: Soil is formed by the breaking apart of rocks due to the action of the Sun, water and living organisms over a long time, sometimes thousands of years. Soil contains sand, insects, worms, decomposed plants and animals, and many tiny organisms. Soil is important because it supports plant growth, provides air spaces for roots, and supports biodiversity. Earthworms help in turning and loosening the soil.
9. Write the uses of rocks and minerals.
Answer: Rocks are used in the construction of houses, buildings, temples, roads, dams and tabletops. Slate is used for roofing and laterite can be used as a building material like bricks. Important rocks include granite, sandstone and marble. Rocks are made of minerals. Metals such as aluminium, gold, copper and iron are extracted from minerals. Minerals are used in airplanes, cars, jewellery, cosmetics and electronic equipment.
10. Explain fossil fuels and why overuse of fossil fuels is harmful.
Answer: Fossil fuels include coal, petroleum and natural gas. They are formed from remains of microorganisms and plants buried deep inside Earth and take millions of years to form. Petrol, diesel and kerosene are obtained from petroleum. Natural gas is used for cooking, electricity generation and as CNG. Coal is mainly used to produce electricity. Overuse of fossil fuels is harmful because they are limited and burning them releases smoke and carbon dioxide, causing air pollution.
Case-Study Based Questions
Case Study 1: Breathing Exercise
Bhoomi and Surya join Ajji in a breathing exercise. They take deep breaths and try to hold their breath for some time. They realise that holding breath for too long is uncomfortable.
Q1. Why is it difficult to hold our breath for a long time?
Answer: Because our body needs oxygen to perform its functions.
Q2. Which gas in air is essential for survival?
Answer: Oxygen.
Q3. What lesson does this activity teach?
Answer: It teaches that air and oxygen are essential for life.
Case Study 2: Making a Firki
Surya makes a paper firki and runs with it. The firki rotates when air moves across it. Ajji explains that windmills work in a similar way.
Q1. What makes the firki rotate?
Answer: Wind or moving air makes the firki rotate.
Q2. What is moving air called?
Answer: Moving air is called wind.
Q3. Write one use of windmills.
Answer: Windmills can generate electricity.
Case Study 3: Water Wastage at Home
A family leaves the tap open while brushing teeth and washing utensils. They also ignore a leaking tap in the kitchen.
Q1. Is water being used judiciously?
Answer: No, water is being wasted.
Q2. Suggest two ways to reduce wastage.
Answer: Turn off taps when not in use and fix leaking taps.
Q3. Why should water be conserved?
Answer: Freshwater is limited and not equally available to everyone.
Case Study 4: Energy from the Sun
Bhoomi sees a cow grazing grass in a field. Surya says the cow gets energy from the Sun indirectly because grass needs sunlight to grow.
Q1. Is Surya correct?
Answer: Yes, Surya is correct.
Q2. How does the cow get energy from the Sun indirectly?
Answer: Grass uses sunlight to grow, and the cow gets energy by eating grass.
Q3. What is the main source of energy on Earth?
Answer: The Sun.
Case Study 5: City Air and Fossil Fuels
When Bhoomi and Surya return to the city, they notice smoke from vehicles and the air smells polluted. Their mother explains that burning fossil fuels causes smoke.
Q1. Which fuels commonly used in vehicles cause pollution?
Answer: Petrol and diesel.
Q2. Name one cleaner vehicle fuel mentioned in the chapter.
Answer: CNG.
Q3. Suggest one way to reduce air pollution.
Answer: Use public transport, cycle, walk for nearby places or use electric vehicles.
Assertion-Reason Questions
Choose the correct option:
A. Both Assertion and Reason are true and Reason is the correct explanation.
B. Both Assertion and Reason are true but Reason is not the correct explanation.
C. Assertion is true but Reason is false.
D. Assertion is false but Reason is true.
1. Assertion: Oxygen is essential for survival. Reason: Our body needs oxygen to perform its functions.
Answer: A
2. Assertion: Air contains only oxygen. Reason: Air is a mixture of gases.
Answer: D
3. Assertion: Moving air is called wind. Reason: Wind can rotate a firki.
Answer: B
4. Assertion: Ocean water is directly fit for drinking. Reason: Ocean water is saline.
Answer: D
5. Assertion: Rainwater harvesting helps conserve water. Reason: It collects and stores rainwater for later use.
Answer: A
6. Assertion: The Sun is the main source of energy on Earth. Reason: Plants use sunlight to prepare food.
Answer: A
7. Assertion: Forests support biodiversity. Reason: Forests provide food and shelter to many living beings.
Answer: A
8. Assertion: Soil forms very quickly in a few days. Reason: Soil is formed by breaking apart of rocks over a long time.
Answer: D
9. Assertion: Fossil fuels are non-renewable resources. Reason: They take millions of years to form.
Answer: A
10. Assertion: Air, water and forests are renewable resources. Reason: They get renewed or restored by natural processes within a reasonable time.
Answer: A
Competency-Based and Critical Thinking / HOTS Questions
1. Why should we not waste water even though Earth has a lot of water?
Answer: Most water on Earth is saline and not fit for daily use. A very small fraction of freshwater is easily accessible. Therefore, water should not be wasted.
2. A student says, “The cow gets energy only from grass, not from the Sun.” Is this completely correct?
Answer: No. The cow eats grass, but grass grows using sunlight. So the cow gets energy from the Sun indirectly through grass.
3. Why is cutting a large forest area harmful for soil?
Answer: Tree roots hold soil and prevent it from being washed away. When trees are cut, soil becomes loose and can be eroded. Fallen leaves also stop adding nutrients to soil.
4. Why is it difficult to regrow forests?
Answer: Forests take many years to develop. Trees grow slowly, animals and plants depend on each other, and restoring lost biodiversity takes a long time.
5. Why are fossil fuels harmful even though they are useful?
Answer: Fossil fuels are useful for transport, cooking and electricity, but they are limited and burning them produces smoke and carbon dioxide, causing air pollution.
6. Why is CNG considered cleaner than petrol or diesel?
Answer: CNG causes less pollution compared to petrol or diesel. Therefore, it is considered a cleaner fuel for vehicles.
7. Why should we collect only fallen fruits from forests instead of plucking all fruits?
Answer: Fruits on trees serve as food for animals and birds. Their seeds can spread through droppings and help new trees grow. This supports forest regeneration.
8. Why is rainwater harvesting important in cities?
Answer: Cities use large amounts of water and often face water shortage. Rainwater harvesting stores rainwater and reduces pressure on freshwater sources.
9. What would happen if there were no sunlight for a week?
Answer: We may need artificial lighting during the day. Solar panels would produce less electricity, drying of clothes and food items would slow down, and plants would not get enough sunlight for making food.
10. Why should natural resources be used judiciously?
Answer: Natural resources support life and meet our needs. If we waste or pollute them, future generations may face shortages. Judicious use helps protect the environment and save resources for the future.
Diagram-Based Questions
Diagram 1: Composition of Air
Nitrogen
78%
Oxygen
21%
Other Gases
1%
Question: Which gas is present in the highest percentage in air?
Answer: Nitrogen.
Diagram 2: Wind Energy
Question: What makes a windmill rotate?
Answer: Wind makes a windmill rotate.
Diagram 3: Water Conservation
Question: Which method stores rainwater for later use?
Answer: Rainwater harvesting.
Diagram 4: Sun as Main Source of Energy
Question: How does a cow get energy from the Sun indirectly?
Answer: Grass uses sunlight to grow, and the cow gets energy by eating grass.
Diagram 5: Classification of Natural Resources
Renewable
Air, water, forests
Non-renewable
Coal, petroleum, natural gas, minerals, rocks, soil
Question: Why is coal non-renewable?
Answer: Coal takes millions of years to form and is found in limited quantity.
Quick Revision Box
- Natural resources are resources provided by nature.
- Air, water, sunlight, forests, soil, rocks, minerals and fossil fuels are natural resources.
- Human-made resources are made by humans using natural resources.
- Air contains 78% nitrogen, 21% oxygen and 1% other gases.
- Oxygen is essential for survival.
- Moving air is called wind.
- Windmills use wind energy to generate electricity and pull water.
- Water is used for drinking, cooking, washing, cleaning, agriculture and industry.
- Most water on Earth is saline and not directly usable.
- Only a small amount of freshwater is easily accessible.
- Rainwater harvesting means collecting and storing rainwater.
- Bawadi and Vav are traditional stepwells for water harvesting.
- The Sun is the main source of energy on Earth.
- Solar panels convert solar energy into electricity.
- Forests provide food and shelter to many living beings.
- Van Mahotsav is celebrated in July to plant trees and spread awareness.
- Chipko movement helped protect trees from being cut.
- Soil is formed by breaking apart of rocks over a long time.
- Earthworms help turn and loosen soil.
- Rocks are used for houses, roads, dams, roofing and tools.
- Minerals are used to extract metals and make useful products.
- Coal, petroleum and natural gas are fossil fuels.
- Fossil fuels are non-renewable resources.
- Air, water and forests are renewable resources.
- Natural resources must be used judiciously.
Important Exam Tips
Interactive Quiz
Choose the correct answer and click submit.
Frequently Asked Questions
1. What are natural resources?
Natural resources are resources provided by nature, such as air, water, sunlight, forests, soil, rocks, minerals and fossil fuels.
2. What is the composition of air?
Air contains about 78% nitrogen, 21% oxygen and 1% argon, carbon dioxide and other gases.
3. What is wind?
Moving air is called wind.
4. Why is water precious?
Water is precious because all living beings need it and only a small fraction of freshwater is easily accessible.
5. What is rainwater harvesting?
Rainwater harvesting is the collection and storage of rainwater for later use.
6. Why is the Sun called the main source of energy?
The Sun gives heat and light, helps plants prepare food, and supports energy flow to animals and humans.
7. Why are forests important?
Forests provide food, shelter, support biodiversity, protect soil and give many useful products.
8. What are fossil fuels?
Fossil fuels are fuels formed from buried remains of ancient microorganisms and plants. Coal, petroleum and natural gas are fossil fuels.
9. What are renewable resources?
Renewable resources are resources that get renewed, replenished or restored by natural processes within a reasonable time.
10. What are non-renewable resources?
Non-renewable resources are limited resources that do not get replenished within a reasonable period, such as coal, petroleum and natural gas.
Final Conclusion
The chapter Nature’s Treasures teaches that air, water, sunlight, forests, soil, rocks, minerals and fossil fuels are valuable resources provided by nature. These resources support life and make human life comfortable. However, many resources are limited or take a very long time to form. Therefore, we must conserve water, protect forests, reduce pollution, save fossil fuels, use renewable energy and use all natural resources responsibly.
Leave a Reply