NCERT Solutions for Class 6 Science (Curiosity) Chapter 11: Nature’s Treasures

These Class 6 Science Curiosity Chapter 11 solutions cover Nature’s Treasures from the new NCF-2023 textbook (2026–27). The chapter introduces the natural resources that nature gives us — air, water, energy from the Sun, forests, soil, rocks, minerals and fossil fuels — and explains how to classify them as renewable or non-renewable and why we must use them wisely. Every “Let us enhance our learning” question is reproduced verbatim and answered in clear, exam-ready style.

Class: 6 Subject: Science Book: Curiosity Chapter: 11 Type: Natural resources & conservation Session: 2026–27
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Class 6 Science Curiosity Chapter 11 Solutions – Overview

In Nature’s Treasures, Bhoomi and Surya visit their Ajji’s village on the edge of a forest in the Western Ghats and discover the many gifts of nature. The chapter explains that air is a mixture of gases (78% nitrogen, 21% oxygen, and 1% argon, carbon dioxide and others) and supplies the oxygen we need to survive; moving air is wind, which can turn a firki or a windmill to generate electricity. Water covers about two-thirds of Earth, but most is salty, so we must conserve precious freshwater through methods like rainwater harvesting. The Sun is the main source of energy for all living beings. Forests, soil, rocks, minerals and fossil fuels (coal, petroleum, natural gas) are other natural treasures. Resources are classified as renewable (renewed in a reasonable time, e.g. air, water, forests) or non-renewable (limited and not replenished quickly, e.g. minerals, soil, rocks, fossil fuels). The big message: use natural resources judiciously.

Key Concepts & Definitions

The 78% / 21% / 1% figures are rounded values for dry air. Real air also contains a variable amount of water vapour. “Renewable” does not mean inexhaustible: forests need time to regrow and local clean-water supplies can be depleted. See NOAA’s atmosphere explanation.

Natural resources: resources we get from nature that are essential to sustain life — air, water, energy from the Sun, forests, soil, rocks, minerals and fossil fuels.

Human-made resources: useful things created by human beings, such as electric bulbs, furniture, solar panels and bicycles.

Composition of air: a mixture of gases — nitrogen 78%, oxygen 21%, and argon, carbon dioxide and other gases together 1%.

Wind: moving air; it rotates a firki and the wings of a windmill, which can run flour mills, pull up water or generate electricity.

Freshwater & rainwater harvesting: most water on Earth is saline; only a small fraction is usable freshwater. Collecting and storing rainwater (e.g. stepwells — Bawadi in Rajasthan, Vav in Gujarat) for later use is rainwater harvesting.

Fossil fuels: petroleum, natural gas and coal, formed over millions of years from the buried remains of microorganisms and plants; found in limited quantities.

Renewable resources: resources that get renewed, replenished or restored by natural processes within a reasonable time — air, water, forests.

Non-renewable resources: resources in limited quantities that are not replenished within a reasonable time — minerals, soil, rocks, coal, petroleum, natural gas.

“Let us enhance our learning” — NCERT Solutions

These original explanations cover Questions 1–16 on pages 227–229 of NCERT Curiosity, Reprint 2026–27. The picture questions and resource chart have been checked against the textbook.

1. Fig. 11.9 shows items related to natural resources. Match them with their jumbled up names. Make another table and write the names of these resources. Classify these resources as renewable or non-renewable.

ANSWER The jumbled names are unscrambled as follows: ocrk → rock, refost → forest, ndiw → wind, atwre → water. The names and their classification are shown below:
Jumbled nameResource (correct name)Renewable / Non-renewable
ocrkRockNon-renewable
refostForestRenewable
ndiwWind (air)Renewable
atwreWaterRenewable

Match the pictures from top to bottom: running tap → water (atwre); wind turbine → wind (ndiw); trees → forest (refost); stone → rock (ocrk). The turbine is human-made; the natural resource it uses is wind.

2. State whether the following statements are True [T] or False [F]. If False, correct them.

(i) Nature has all the resources to meet human needs. [ ]

ANSWERTrue [T]. Nature provides the resources required for survival, such as air, water, sunlight, forests, soil and minerals. This does not mean supplies are unlimited or equally accessible; we must use them responsibly.

(ii) Machines are a resource found in nature. [ ]

ANSWERFalse [F]. Correction: Machines are human-made resources; they are made by human beings and are not found in nature.

(iii) Natural gas is a non-renewable resource. [ ]

ANSWERTrue [T]. Natural gas is a fossil fuel that takes millions of years to form and is found in limited quantities, so it is non-renewable.

(iv) Air is a renewable resource. [ ]

ANSWERTrue [T]. Air is renewed by natural processes within a reasonable period of time, so it is a renewable resource.

3. Fill in the blanks using the most appropriate option—

(i) A fuel that is commonly used in two wheelers like scooters or bikes is……… (a) Kerosene (b) Petrol (c) Diesel (d) LPG

ANSWER(b) Petrol. Two-wheelers such as scooters and bikes most commonly run on petrol.

(ii) An example of a renewable resource is ……………… (a) Coal (b) Water (c) Natural gas (d) Petrol

ANSWER(b) Water. Water is renewed through natural processes (such as the water cycle), while coal and natural gas are fossil fuels, and petrol is made from petroleum; all three options are non-renewable.

4. Classify the following as renewable or non-renewable resources—coal, natural gas, forests and minerals.

ANSWER
ResourceClassification
CoalNon-renewable
Natural gasNon-renewable
ForestsRenewable
MineralsNon-renewable

5. Why do we say that petroleum is a non-renewable resource?

ANSWERPetroleum is formed from the remains of microorganisms and plants buried deep inside the Earth, and this formation takes millions of years. It is found in limited quantities, and once it is used up, it cannot be produced or replenished within a reasonable period of time. Because it gets exhausted and is not renewed quickly, petroleum is called a non-renewable resource.

6. It is difficult to regrow forests. Justify this statement.

ANSWERA forest is not just a group of trees — it is a complex natural home for many plants, animals, birds and insects living together in balance. Trees take many years to grow tall and mature, and it takes even longer for a whole forest, with its rich soil and variety of life forms, to develop. When a forest is cut down on a large scale, it cannot be restored quickly; it takes many years, sometimes decades, for the lost forest to regenerate. That is why it is difficult to regrow forests, and we must preserve and use them responsibly.

7. Make a list of five daily activities in which you use natural resources. Suggest ways by which you can reduce their use.

ANSWER
Daily activityNatural resource usedWay to reduce its use
BathingWaterTake a bucket bath instead of a long shower; turn off the tap.
Travelling to schoolFossil fuel (petrol/diesel)Walk, cycle, carpool or use public transport.
Lighting and fans at homeEnergy sources used to generate electricity, such as coal, sunlight, wind or flowing waterSwitch off lights and fans when not needed; use solar energy.
Cooking foodNatural gas / LPGUse a lid on pots and a solar cooker; cook efficiently.
Using paper / notebooksForests (wood)Use both sides of paper and recycle paper to save trees.
(Your own list of activities is accepted.)

8. List four activities that are possible due to the presence of air.

ANSWER Four activities possible due to the presence of air: (i) Breathing — living beings breathe in the oxygen present in air to survive. (ii) Rotating a firki or windmill — moving air (wind) turns the wings of a windmill to generate electricity, pump water or run flour mills. (iii) Drying of clothes — air helps wet clothes dry faster. (iv) Burning of fuel — the oxygen in air is needed for fuels to burn, for example in cooking and in vehicles.

9. How can you contribute towards enhancing the green cover of your locality? Make a list of actions to be taken.

ANSWER Actions to enhance the green cover of my locality: (i) With permission and adult guidance, plant suitable native trees in appropriate places and take part in events like Van Mahotsav. (ii) Water and care for newly planted trees so that they survive and grow. (iii) Stop people from cutting trees unnecessarily and create awareness about protecting forests. (iv) Grow plants in pots, balconies and terraces (kitchen gardens) where there is little space. (v) Avoid littering and keep green areas clean so that plants stay healthy.

10. In the given illustration, we see that food is being cooked.
Answer the following questions—

(i) What type of energy is being used for cooking?

ANSWERIn the illustration, food is being cooked using solar energy (energy from the Sun), as in a solar cooker.

(ii) Name one benefit and one drawback of using this type of energy for cooking.

ANSWER Benefit: A solar cooker uses renewable sunlight and burns no fuel during cooking, so it produces no combustion smoke at the point of use. Sunlight is free, although the equipment has a cost. Drawback: The concentrating cooker pictured needs strong direct sunlight. Cloud cover reduces its performance, and it cannot cook at night without stored heat or another energy source. Cooking time depends on the design, sunlight and food.
Parallel sunlight rays reflect from a curved solar-cooker dish towards a dark cooking pot near the focus.
Question 10: a concentrating solar cooker reflects sunlight towards a pot. Schematic cross-section; not to scale. Tap to view at full size.

11. Cutting down trees on a large scale impacts the quality of the soil. Why do you think it is so?

ANSWERThe roots of trees hold on to the soil and prevent it from being washed away by rain or blown away by wind. The leaves that fall from trees decay and enrich the soil with nutrients, keeping it fertile. When trees are cut on a large scale, the roots no longer bind the soil, so the fertile top layer is easily washed or blown away (soil erosion). There are also fewer fallen leaves to decay and add nutrients. As a result, the soil loses its fertility and becomes poor in quality.

12. Explain two ways in which human activities pollute the air. Propose one action which can help in reducing air pollution.

ANSWERTwo sources: (i) vehicle engines burning petrol or diesel release gases such as nitrogen oxides and may release fine particles; (ii) factories and power stations burning fuels can release particles and harmful gases. Carbon dioxide from fuel use also contributes to climate change.One action: use public transport, walk or cycle when practical and safe to reduce the number of fuel-burning journeys. Electric vehicles have no tailpipe exhaust, but their overall impact also depends on electricity generation and manufacturing.

13. A family uses solar panels to generate electricity, a gas stove to cook food and a windmill for pumping water from a well. What would happen if there were no sunlight for a week?

ANSWERSolar panels: if no sunlight reaches them at all, they cannot generate solar electricity. The family would need stored electricity or another supply. Cloudy weather is different: panels can usually generate some electricity from diffuse daylight, though output is reduced.Gas stove: it can continue cooking while gas, such as LPG or natural gas, is available; it does not need sunlight at the time of use.Wind pump: it can continue only while there is sufficient wind and water in the well. It does not require direct sunlight at that moment, but wind patterns are largely driven by the Sun’s uneven heating of Earth, so operation is not guaranteed throughout the week.For the cloudy-day distinction, see the Australian Government explanation of solar panels.

14. Fill up the blanks using the following terms—(fossil fuels, forest, air, petroleum, coal, water and non-renewable resource)

ANSWER The natural-resources flow chart can be completed as follows:
Position in chartCorrect term
Natural Resources → Renewable Resources (examples)air, water and forest
Natural Resources → Non-renewable resource (category)non-renewable resource
Non-renewable resource → Fossil fuels (group)fossil fuels
Fossil fuels (examples, with Natural gas)coal and petroleum
The chart’s right-hand examples are air, water and forest. Its left-hand category is non-renewable resource, followed by fossil fuels, then coal, natural gas and petroleum. Fossil fuels are one group of non-renewable resources; rocks and minerals are other examples.
Completed NCERT resource chart: non-renewable resources include fossil fuels—coal, natural gas and petroleum; renewable examples are air, water and forest.
Question 14: completed chart with the same branch order as the textbook. Fossil fuels are one subgroup of non-renewable resources. Tap to view at full size.

15. There is an increasing demand of trees to meet the requirements of industries and for housing. Therefore, trees are being felled. Is it justified? Discuss and prepare a brief report.

ANSWERBrief report: Cutting trees on a large scale only to meet the needs of industries and housing is not fully justified. While some wood is needed for our daily life, forests give us pure air, hold the soil together, provide food and shelter to wild animals and birds, and help bring rain. Large-scale felling reduces the green cover, causes soil erosion, increases air pollution and destroys the homes of many living beings. It takes many years to regrow a forest. Therefore, instead of cutting trees freely, we should use wood carefully, recycle paper and wood, protect existing forests, avoid unnecessary clearing, restore damaged areas with suitable native species, and use forest products responsibly. Planting saplings cannot immediately replace a mature forest and its biodiversity. Sustainable use, not unlimited felling, is the right path. (Your own reasoned report is accepted.)

16. Propose a plan to use less water in your school. What steps would you take to make this plan happen and how would it help the environment?

ANSWERPlan: first record the school’s water use for one week, using meter readings if available, and note leaking taps or wasteful practices.Actions: ask school staff to repair leaks; use suitable water-saving fittings; turn taps off after use; and water plants carefully. Maintain drinking water and handwashing—saving water should not reduce hygiene.Implementation: form a teacher-supervised student group, assign checks, agree a realistic target and review weekly readings. Ask staff about a properly designed, covered rainwater-harvesting system for appropriate non-drinking uses. Reuse water only when staff confirm it is suitable; do not put water containing detergents, chemicals or sewage on plants.Benefit: less freshwater is wasted and less energy is needed for pumping and treatment. Compare use before and after the plan to see whether it works.

Common Mistakes to Avoid

Watch out for these

  • Calling soil, rocks and minerals renewable — they form over thousands to millions of years, so they are non-renewable.
  • Mixing up the air composition — remember nitrogen 78%, oxygen 21%, and argon + carbon dioxide + others = 1%.
  • Thinking we can live longest without oxygen — we can survive days without food or water but only minutes without oxygen.
  • Confusing natural and human-made resources — machines, bulbs and bicycles are human-made, not natural.
  • Believing all water on Earth is usable — most water is saline; only a small fraction is accessible freshwater.
  • Forgetting that fossil fuels (coal, petroleum, natural gas) are all non-renewable and cause air pollution when burnt.

Extra Practice Questions

These questions and MCQs are ClearStudy practice, separate from the NCERT exercise.

Short Answer Type Questions

Q1. What is the composition of air?

ANSWERAir is a mixture of gases — about 78% nitrogen, 21% oxygen, and 1% argon, carbon dioxide and other gases.

Q2. Why can we not survive without air even for a few minutes?

ANSWERThe air we breathe contains oxygen, which our body needs to perform its functions. Without oxygen for even a few minutes, the body cannot work, so we cannot survive without air.

Q3. What is rainwater harvesting? Give one traditional example.

ANSWERRainwater harvesting is collecting and storing rainwater in large quantities for later use. A traditional example is the stepwell — Bawadi in Rajasthan and Vav in Gujarat.

Q4. Differentiate between renewable and non-renewable resources with one example each.

ANSWERRenewable resources get renewed or replenished by nature within a reasonable time (e.g. water), while non-renewable resources are limited and are not replenished quickly (e.g. coal).

Q5. Why is the Sun called the main source of energy on Earth?

ANSWERThe Sun gives heat and light to all living beings. Plants use sunlight to make food, animals eat plants, and we get food from both plants and animals. Thus, sunlight supports most food chains and is the main source of energy for life at Earth’s surface.

Long Answer Type Questions

Q1. What are fossil fuels? How are they formed and why must we conserve them?

ANSWERFossil fuels are petroleum, natural gas and coal. They are formed from the remains of microorganisms and plants that got buried deep inside the Earth and were slowly converted into these fuels over millions of years. From petroleum we get petrol, diesel and kerosene. Fossil fuels are found in limited quantities and take an extremely long time to form, so they are non-renewable — once used, they get exhausted. Burning them also produces smoke and carbon dioxide, which pollute the air. Therefore, we must conserve fossil fuels by walking or cycling to nearby places, using public transport, and switching to cleaner alternatives so that they last longer and the environment stays healthy.

Q2. How can water get polluted, and what can we do to conserve and protect it?

ANSWERWater gets polluted when people throw trash, plastic bags and wrappers into rivers, ponds and lakes, and when waste from homes and industries is dumped into water sources. Polluted water is unfit for living beings. As freshwater is limited, we must use it judiciously: turn off taps when not in use, fix leakages, recycle water, and practise rainwater harvesting like stepwells (Bawadi, Vav). We should also stop dumping waste into water bodies so that water stays clean and fit for all living beings. Observing days like World Water Day (22nd March) reminds us of the importance of conserving water.

Q3. Describe how wind energy is useful to us.

ANSWERMoving air is called wind, and it carries energy. A firki (paper pinwheel) rotates when wind blows on it, and a windmill works in the same way — the wind rotates its wings. Windmills can be used to run flour mills, to pull up water from a well, and to generate electricity. A windmill farm is an area with a large number of windmills that use wind energy to produce electricity, such as the Muppandal Wind Farm in Tamil Nadu, the Jaisalmer Wind Park in Rajasthan and the Brahmanvel Wind Farm in Maharashtra. Wind is renewable, and wind turbines generate electricity without burning fuel during operation. Building and installing them still uses materials and energy.

MCQs & Assertion–Reason

1. The gas present in the largest amount in air is:

(a) oxygen    (b) carbon dioxide    (c) nitrogen    (d) argon

2. The percentage of oxygen in air is about:

(a) 78%    (b) 21%    (c) 1%    (d) 50%

3. Moving air is called:

(a) breeze only    (b) wind    (c) storm only    (d) firki

4. Which of the following is a renewable resource?

(a) coal    (b) petroleum    (c) forest    (d) natural gas

5. Petrol, diesel and kerosene are obtained from:

(a) coal    (b) petroleum    (c) natural gas    (d) water

6. The main source of energy on Earth is:

(a) coal    (b) wind    (c) the Sun    (d) water

7. Stepwells known as Bawadi and Vav are used for:

(a) mining    (b) water harvesting    (c) generating electricity    (d) drying chillies

8. Which of the following is a human-made resource?

(a) air    (b) soil    (c) bicycle    (d) forest

9. Which of these is a non-renewable resource?

(a) water    (b) air    (c) minerals    (d) forest

10. The famous Chipko movement was associated with:

(a) saving water    (b) protecting trees    (c) reducing air pollution    (d) mining marble

Answer key: 1-(c), 2-(b), 3-(b), 4-(c), 5-(b), 6-(c), 7-(b), 8-(c), 9-(c), 10-(b).

For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.

A-R 1. Assertion: Fossil fuels are called non-renewable resources.

Reason: They take millions of years to form and are found in limited quantities.

A-R 2. Assertion: We must conserve freshwater.

Reason: Most of the water on Earth is saline and only a small fraction of freshwater is easily accessible.

A-R 3. Assertion: A solar cooker does not work at night.

Reason: A solar cooker uses natural gas to cook food.

A-R 4. Assertion: Cutting trees on a large scale lowers the quality of soil.

Reason: Roots hold the soil and fallen leaves decay to enrich it, so removing trees causes soil to wash away and lose nutrients.

A-R 5. Assertion: Air is a non-renewable resource.

Reason: Air is renewed by natural processes within a reasonable period of time.

Answer key: 1-(A), 2-(A), 3-(C), 4-(A), 5-(D).

Quick Revision Summary

  • Resources we get from nature are natural resources: air, water, energy from the Sun, forests, soil, rocks, minerals and fossil fuels.
  • Things made by humans (bulbs, furniture, solar panels, bicycles) are human-made resources.
  • Air = 78% nitrogen + 21% oxygen + 1% (argon, CO₂ and others); moving air is wind, used in windmills.
  • Most water is saline; conserve freshwater by saving water and rainwater harvesting (Bawadi, Vav).
  • The Sun is the main source of energy; fossil fuels (coal, petroleum, natural gas) form over millions of years.
  • Renewable resources (air, water, forests) can be replenished naturally, but renewal may take time and does not justify overuse; non-renewable resources (minerals, soil, rocks, fossil fuels) do not — use all of them judiciously.

Real-life Applications

The lessons of Nature’s Treasures appear all around us. Windmill farms like Muppandal in Tamil Nadu and the Jaisalmer Wind Park turn free wind into electricity; solar panels on rooftops, street lights and traffic signals harvest sunlight; and homes, schools and stepwells across India store rainwater for the dry season. Switching to CNG, LPG and electric vehicles reduces the smoke from fossil fuels, while events like Van Mahotsav and the spirit of the Chipko movement remind us to protect forests and soil. Practising small habits — turning off taps, walking or cycling, using both sides of paper, and planting trees — helps conserve nature’s treasures for the future, exactly as Gandhiji said: “Earth provides enough to satisfy every man’s need but not for every man’s greed.”

How to write a clear answer

Memorise the air composition (78% / 21% / 1%) and the two lists — renewable (air, water, forests) and non-renewable (minerals, soil, rocks, coal, petroleum, natural gas). In “justify” answers (e.g. why petroleum is non-renewable, why forests are hard to regrow), always give the reason of time taken to form/grow and limited quantity. For diagram questions like the natural-resources chart, place fossil fuels under non-renewable and list coal, petroleum and natural gas as examples. Use the textbook’s real examples — Bawadi, Vav, Chipko movement, Van Mahotsav — to show you have read the chapter.

Frequently Asked Questions

What is Class 6 Science Curiosity Chapter 11 about?

Chapter 11, Nature’s Treasures, is about natural resources — air, water, energy from the Sun, forests, soil, rocks, minerals and fossil fuels. It explains how to classify resources as renewable or non-renewable and why we should conserve and use them judiciously.

What is the difference between renewable and non-renewable resources?

Renewable resources get renewed, replenished or restored by natural processes within a reasonable period of time (for example air, water and forests). Non-renewable resources are limited in quantity and are not replenished within a reasonable time (for example minerals, soil, rocks, coal, petroleum and natural gas).

What is the composition of air according to this chapter?

Air is a mixture of gases — about 78% nitrogen, 21% oxygen, and 1% argon, carbon dioxide and other gases together.

Are these Class 6 Science Curiosity Chapter 11 solutions free?

Yes. All solutions are free and follow the official NCERT Curiosity textbook for 2026–27.

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