Maharashtra Board Class 7 Science Chapter 16 Natural Resources Solutions

Question 1. Describe natural resources with reference to the following 3 types:

Question a. Mineral resources
Answer: Mineral wealth has an important place among natural resources. The rocks on the earth are mainly made of minerals. These minerals can be obtained by mining. Minerals that contain a high proportion of metals are ores,
(i) Minerals are formed from the magma in the earth's crust and the lava from the eruption of volcanoes when they cool and get transformed into crystals e.g. magnetite, mica,
(ii) Minerals get transformed from one form into another due to large changes in temperature and pressure e.g. Diamond, Graphite,
(iii) There are 3 types of minerals according to their properties Non-metal minerals: e.g. mica, sulphur, potash, diamond.
• Metals minerals: e.g. Iron, gold, silver, tin, bauxite, platinum.
• Energy minerals: e.g. Coal, mineral oil, natural gas, diamond, ruby, sapphire, jade are used as gems.
Some important minerals and ores are Iron ore, manganese, bauxite, copper and mica.
In simple words: Natural resources like minerals, forests, and oceans are vital. Minerals are extracted from rocks and can be metallic or non-metallic. Forests provide wood, medicinal plants, and support diverse life. Oceans cover 70% of Earth, offering energy, minerals, and bio-resources like fish and gems.

🎯 Exam Tip: Remember the examples for each type of mineral and their uses for better scoring.

Question b. Forest resources
Answer:
1. A forest is a natural habitat of plants, animals and microbes.
2. Forest perform certain specific protective and productive functions.
3. We get different types of wood and many medicinal plants from forests.
4. Forest wealth includes fire wood, trees like teak, mahogany, neem, acacia, subabhul, fibers, paper, rubber, gum, aromatic substances.
5. We get fragrant essential oils from lemon grass, vanilla, kewada, vetiver (khus) and eucalyptus.
6. Sandalwood and oil of eucalyptus are used for making soaps, cosmetics and incense sticks.
7. Also we get fruits, bulbs, roots, honey, sealing wax, dyes from forest.
8. Many medicinal plants adulsa, bel, neem, periwinkle, cinnamon, are used for treatment of various diseases such as cough cold, malaria, diarrhoea, cancer, fever and cold.
9. Wood is used as a source of energy for cooking purpose and for keeping warm.
10. For making furniture, tool handles, matches, bridges, boats etc.
11. Bamboos are used for matting, flooring, basket, ropes, rafts, cots etc.
12. Bamboos, wood are used in the manufacture of rayon, yams, artificial silk-fibers.
In simple words: Forests are diverse ecosystems that provide habitat for many species. They offer numerous resources like wood for fuel and construction, medicinal plants for health, and various raw materials such as fibers, rubber, and essential oils, all while performing vital ecological functions.

🎯 Exam Tip: List a variety of products obtained from forests, including medicinal plants and industrial raw materials.

Question c. Ocean resources
Answer:
1. Oceans occupy about 70% of a earth's surface.
2. Energy can be obtained on a large scale from oceans.
3. Sea waves at high and low tide and ocean currents are being used for generation of power.
4. There are billions of tons of minerals dissolved in ocean water.
5. There are large reserves of tin, chromium, potassium, phosphates, copper, zinc, iron, lead, thorium, manganese, sulphur, uranium in the ocean and sea beds.
6. Also we get many types of gems, conches, shells and pearls from the sea.
7. There are large reserves of mineral oil and natural gas at the bottom of sea.
8. We get fishes, dried shrimp, shells, fungi, shark, cod fish and sea cucumber from the ocean.
In simple words: Oceans are vast reservoirs of natural resources, covering most of the Earth. They provide immense potential for energy generation from waves and currents, contain dissolved minerals, and are rich sources of mineral oil, natural gas, and various marine life like fish, shrimp, and pearls.

🎯 Exam Tip: Focus on both energy resources and mineral/biological resources from oceans when describing them.

Question 2. Write answers to the following questions in your own words.

Question a. What is meant by fossil fuel? What are their types?
Answer:
1. Fossil fuels (such as coal or natural gas) are formed in the earth from dead plants and animals, due to high pressure from above and the heat from the earth's interior.
2. The dead plants, animals get transformed into fossil fuel.
3. There are three types of fossil fuels which can be used for energy production, Coal, oil and natural gas.
a. Coal:
1. Coal is a solid fossil fuel formed over millions of years by the decay of land vegetation,
2. Coal is a store house of carbon. Coal is found in mines,
3. It is like porous, hard, black rock.
4. It is burnt to obtain heat energy.
5. It is used as a fuel in thermal power plants and to run boilers and railway engines, for cooking and baking bricks.
6. Anthracite is the coal of the highest grade.
7. Producer gas and water gas are obtained from coal.
b. Mineral oil:
1. Mineral oil is the liquid fuel formed by the decomposition of organic substances buried underground,
2. The underground mineral oil is extracted through oil wells.
3. Mineral oil is found mainly in oil sands, shale, sandstone and limestone at a depth of about 1000 to 3000 metres.
4. Mineral oil is also known as petroleum or crude oil. It is greenish-brown in colour.
5. Petroleum is a mixture of many compounds mainly of the hydrocarbon type.
6. It also contains compounds of oxygen, nitrogen and sulphur.
7. Petroleum is extracted through oil wells and refined by fractional distillation to separate other components,
8. Aviation petrol, gasoline, diesel, kerosene, naphtha, lubricating oil, tar are all obtained from petroleum.
9. They are used as fuel and for production of dyes, pesticides, perfumes and artificial fibres.
c. Natural gas:
1. Natural gas is an important fossil fuel.
2. It is lighter than air. It is found with petroleum in underground oil wells and in some places as natural gas alone.
3. The main component of natural gas is methane (CH4), ethane (C2H6), propane (C3H8) and butane (C4H10) are present in small proportions.
4. This gas is highly flammable.
5. This fuel can be carried over long distance by means of a gas pipeline.
6. In absence of pipeline, it is transformed under high pressure into compressed natural gas (CNG) and liquefied natural gas (LNG).
In simple words: Fossil fuels are energy sources formed from the remains of ancient plants and animals over millions of years under intense heat and pressure. The main types are coal (solid), mineral oil (liquid, also called petroleum), and natural gas (gaseous), all used for generating power and various other purposes.

🎯 Exam Tip: Clearly define fossil fuels and then list and describe each of the three main types with their key characteristics and uses.

Question b. Make a list of the components we obtain from mineral oil.
Answer:
1. Mineral oil is the liquid fuel. It is also known as petroleum or crude oil. Petroleum is refined by fractional distillation to separate other components.
2. Aviation petrol, gasoline, diesel, kerosene, naphtha, lubricating oil, tar are the components we obtain from mineral oil.
In simple words: From mineral oil, also known as crude oil or petroleum, we obtain various products through refining processes. These include aviation petrol, gasoline, diesel, kerosene, naphtha, lubricating oil, and tar, all essential for transport and industry.

🎯 Exam Tip: Remember to mention fractional distillation as the process for separating components from mineral oil.

Question c. What do we get from forest?
Answer:
1. A forest is a natural habitat of plants, animals and microbes. We get wood, firewood from trees like teak, mahogany, neem, subabhul.
2. Also we get fibers, paper, rubber, gum and aromatic substances.
3. We get many medicinal plants like Adulsa, Bel, Neem, Periwinkle, Cinnamon, Cinchona which are used for treatment of various diseases like cough, cold, diarrhea, fever, cancer, diarrhoea, nausea, malaria.
4. We get fragrant essential oils from lemon grass, vanilla, kewada, khus, eucalyptus.
5. In addition to this we get fruits, bulbs and roots, honey, sealing wax, catechu, dyes from forest.
In simple words: Forests are a rich source of diverse products, including wood for various uses, raw materials like fibers and rubber, fragrant essential oils, and numerous medicinal plants such as Adulsa and Neem used for treating various ailments.

🎯 Exam Tip: Categorize your answer into different types of products from forests (wood, medicinal, raw materials) for a comprehensive response.

Question d. What are the items included in ocean resources? What are their uses?
Answer:
1. Tons of minerals are found in ocean water.
2. They are tin, chromium, phosphates, copper, zinc, iron, lead, manganese, sulphur, uranium etc.
3. We also get many types of gems, conches, shells and pearls from the sea.
4. Mineral oil and natural gas is found at the bottom of sea.

Bio-Resources In Oceans
• Fishes - like pomfret, seer fish as also shrimps
• prawns - they are sources of proteins and vitamins, therefore, mainly used as sea food
• Dried shrimp, Bombay duck powder - used as poultry feed and is a good manure.
• Shells - used for preparation of medicines, ornaments and decorative articles.
• Fungi - used for the production of antibiotics.
• shark and cod fish - used for producing edible oil rich in Vitamins A, D and E.
• Sea cucumbers - used as medicine for treating cancer and tumours.

Mineral Resources From Oceans
• Thorium - used in the production of atomic energy.
• Magnesium - used in the flash bulb of a camera.
• Potassium - the main ingredient in production of soap, glass, fertilizer.
• Sodium - used in the production of cloth and paper.
• Sulphate - used in making artificial silk.
In simple words: Ocean resources include vast quantities of minerals like tin, copper, uranium, and mineral oil, along with natural gas. Bio-resources consist of various fish, shrimp, and other marine organisms used for food, medicine, and industrial purposes, making oceans crucial for human sustenance and economic activity.

🎯 Exam Tip: Differentiate between bio-resources and mineral resources from oceans and provide specific examples for each, including their uses.

Question e. Why should we prevent the wastage of fuels used for vehicles?
Answer:
1. Vehicles are powered by gasoline or diesel petrol.
2. Nowadays compressed natural gas (CNG) is also used.
3. Aviation petrol, gasoline, diesel, we get from petroleum after fractional distillation.
4. Petroleum is a non-renewable source of energy.
5. It is getting depleted day by day and the demand for fuel has increased greatly due to the rapidly growing population.
6. But the reserves of petroleum (fossil fuel) are limited.
7. It is becoming difficult to meet the increased demand. So we should prevent the wastage of fuel.
In simple words: We must prevent the wastage of vehicle fuels because petroleum, a primary source, is non-renewable and its reserves are limited. With a growing population, demand is increasing, making it crucial to conserve these depleting resources for future availability and to avoid supply shortages.

🎯 Exam Tip: Highlight the non-renewable nature and increasing demand as key reasons for fuel conservation.

Question f. Why is the diversity of plants and animals in the forests declining?
Answer:
1. The major causes of biodiversity decline are land use changes, pollution, changes in atmosphere, CO2 concentration, changes in the nitrogen cycle, acid rain, climate alteration and introduction of exotic species.
2. All this is due to population growth.
3. This is the main cause of the loss of biodiversity. More of wood for fuel is been used, more land is required for food production, livestock grazing etc.
4. Rainforest land is converted to industrial and residential usage, so natural habitat of birds, animals is destroyed.
5. Due to population growth most of wild land is converted to crop land. So no space for animals to live, their natural habitat is destroyed.
In simple words: The diversity of plants and animals in forests is declining primarily due to human population growth leading to land use changes, such as conversion of forest land for agriculture, industry, and housing. This, combined with pollution and climate alteration, destroys natural habitats and pushes species towards extinction.

🎯 Exam Tip: Focus on human activities like population growth, land conversion, and pollution as the main drivers of biodiversity loss.

Question g. Write the names of five minerals and the useful substances obtained from them.
Answer: Some important minerals and ores are:
1. Iron ore: It is used for making farming implements, rails of railway tracks etc.
2. Manganese: Compounds of manganese are used in the preparation of medicines and for giving a pink tinge to glass. Manganese is also used in electrical appliances.
3. Bauxite: It contains 55% Aluminium. Therefore, it is used mainly in aeroplanes, transport vehicles and to make electric wire.
4. Copper: It is used to make electric wires as well as in radios, telephones, vehicles, and for making kitchen utensils and statues.
5. Mica: Mica has many uses such as in ayurvedic medicines, dyes, electric machines and equipment, wireless communication equipment, etc.
In simple words: Five important minerals and their uses include: Iron ore for farming tools and railway tracks; Manganese for medicines, glass tinting, and electrical appliances; Bauxite (for Aluminum) in aeroplanes and electric wires; Copper for wiring, vehicles, and utensils; and Mica for medicines, dyes, and electronic equipment.

🎯 Exam Tip: Provide clear examples of each mineral and at least two distinct uses for each to demonstrate a good understanding.

Question h. Name the two important stages in the process of obtaining metals from ores.
Answer: The two important stages in the process of obtaining metals from ores are extraction and purification.
In simple words: The two key steps to get metals from their ores are extraction, where the raw metal is separated from the ore, and purification, where impurities are removed to achieve the desired metal purity.

🎯 Exam Tip: Simply stating "extraction and purification" is sufficient for this question.

Question 3. What steps are taken for protection and conservation of natural resources?

Question a What steps are taken for protection and conservation of natural resources?
Answer:
1. Protection and conservation of natural resources is necessary to protect the natural world. (CNRM) Community Natural Resource Management has been promoted in recent years for biological conservation.
2. The World Conservation Union has been formed. It is the world's leading authority and democratic platform in conservation and sustainability.
3. Young trees should not be cut. More and more trees need to be grown.
4. The stringent restrictions/laws/ Regulations regarding use of forests should be strictly followed. Awareness is being created through Mass media.
In simple words: To protect natural resources, steps include promoting Community Natural Resource Management, forming global organizations like the World Conservation Union, planting more trees and preventing their cutting, and enforcing strict regulations on forest use while raising public awareness through media.

🎯 Exam Tip: Mention both policy/organizational efforts and individual/community actions for conservation.

Question 4. Complete the Flow Chart:

Question a.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक फ्लो चार्ट है जो "Fuels" को दो मुख्य प्रकारों, "Fossil fuels" और [Blank], में विभाजित करता है। "Fossil fuels" को फिर तीन उप-श्रेणियों - "Solid", "Mineral oil", और "Natural gas" में बांटा गया है, जिनमें से "Solid" के नीचे "Peat, lignite, bituminous coal, anthracite" सूचीबद्ध हैं और बाकी दो के नीचे खाली बॉक्स हैं। इस चार्ट को पूरा करना है।
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक पूर्ण फ्लो चार्ट है जो 'Fuels' (ईंधन) को 'Fossil Fuels' और [अन्य प्रकार, यहाँ खाली है] में वर्गीकृत करता है। 'Fossil Fuels' को आगे 'Solid', 'Liquid' और 'Gaseous' में बांटा गया है। 'Solid' के तहत 'Coal' आता है, जिसके उपप्रकार 'Peat, Lignite, Bituminous, Anthracite' हैं। 'Liquid' के तहत 'Mineral oil' है, जिसमें 'Petroleum, Aviation petrol, gasoline, diesel, kerosene, Naphtha, Lubricating oil, tar' शामिल हैं। 'Gaseous' के तहत 'Natural gas' है, जिसके उपप्रकार 'Compressed natural gas (CNG)' और 'liquefied natural gas (LNG)' हैं।
In simple words: The flow chart illustrates the classification of fuels, starting with "Fuels" dividing into "Fossil Fuels" and other categories. Fossil fuels are further broken down into solid (coal varieties), liquid (mineral oil and its derivatives like petrol, diesel), and gaseous forms (natural gas, CNG, LNG), showing the hierarchy of energy sources.

🎯 Exam Tip: For flow chart completion, ensure correct categorization and list all relevant sub-types under each category.

Question 5. How does the economic condition of a nation depend on its natural resources?

Question a. How does the economic condition of a nation depend on its natural resources?
Answer:
1. Natural resources are a necessary condition for economic growth.
2. Three circles enclosed within one another shows how both economy and society are subsets of our planetary ecological system.

ℹ️ चित्र व्याख्या (Diagram Explanation): यह एक वेन डायग्राम है जिसमें तीन संकेंद्रित वृत्त हैं। सबसे बाहरी वृत्त "Environment" को दर्शाता है, मध्य वाला वृत्त "Society" को, और सबसे भीतरी वृत्त "Economy" को दर्शाता है। यह दर्शाता है कि अर्थव्यवस्था समाज का एक हिस्सा है, और समाज पर्यावरण का एक हिस्सा है, जो सभी एक-दूसरे पर निर्भर हैं।
3. Natural resource economics deals with the supply, demand and allocation of the Earth's natural resources.
4. Economic growth is an increase in the value of goods and services produced in an economy.
5. The natural resources of a country depend on the climatic and environmental conditions.
6. Countries having plenty of natural resources enjoy good growth than countries with small amount of natural resources.
7. A country having skilled and educated work force with rich natural resources takes the economy on the growth path, because skilled and educated people can efficiently utilize or exploit natural resources, e.g. Saudi Arabia: their economic growth is high, because they have oil wells.
8. All countries import fuel or oil from them so Saudi Arabia is economically a rich country.
In simple words: A nation's economic condition is heavily reliant on its natural resources because these resources provide the raw materials for production and industry. Abundant resources, combined with a skilled workforce, can significantly boost economic growth, as seen in countries like Saudi Arabia with its oil wealth, leading to higher GDP and trade.

🎯 Exam Tip: Explain the direct link between resource availability, efficient utilization, and economic prosperity, using a relevant example.

Question 6. Which medicinal plants will you grow on your school premises and near your house? Why?

Question a. Which medicinal plants will you grow on your school premises and near your house? Why?
Answer:
1. I will grow tulsi, neem, lemon grass, bel, adulsa, periwinkle, cinnamon, ashwagandha, shatavari, amla, hirda, behda.
2. These plants are used for treatment of various diseases.
• Tulsi - for cough and cold.
• Amla, hirda, behda - Help in digestion of food or any stomach related problems.
• Adulsa - for cough and cold
• Bel - for Diarrhoea
• Neem - Fever and cold
• Periwinkle - Cancer
• Cinnamon - Diarrhoea, nausea.
• Cinchona - Malaria.
• Ashwagandha - It can reduce blood sugar levels. It can reduce stress and anxiety, may reduce symptom of depression.
• Shatavari - has been used for centuries in Ayurveda to support the reproductive system.
• Amla - Excellent source of vitamin C. Amla juice is best tonic to keep you younger for long.
• Hirda - This fruit is commonly called Haritaki. It is used for treating arthritis, dental problems like caries, bleeding gums.
• Behda -(Beleric) is a rejuvenative and laxative, proves beneficial for hair, throat and eyes.
• Tulsi - Tulsi has germicidal, fungicidal, anti-bacterial anti-biotic properties, cures fever. Treats diabetes, protects the heart. Tulsi has anti-oxidant component Eugenol which keeps one's blood pressure under control.
In simple words: I would grow medicinal plants like Tulsi, Neem, Amla, and Ashwagandha on school premises and near my house because they offer various health benefits. Tulsi helps with coughs, Neem for fever, Amla for vitamin C and digestion, and Ashwagandha for stress and blood sugar, making them easily accessible for common ailments.

🎯 Exam Tip: Name at least 3-5 specific medicinal plants and clearly state their primary uses or benefits.

Project:

Question 1. Collect conches and shells of various shapes and colours and make a decorative article.
Answer: [No answer provided in the source for this project activity, as it is a practical task for students.]
In simple words: This project involves collecting diverse conches and shells, then arranging or combining them creatively to craft a decorative item.

🎯 Exam Tip: For practical projects, focus on creativity, organization, and the proper display of collected items.

Question 2. Collect information about the mines of various minerals.
Answer: [No direct answer provided in the source, as it is a research-based task for students.]
In simple words: This project requires researching and gathering information about different mineral mines, including their locations, the types of minerals extracted, and their economic significance.

🎯 Exam Tip: When presenting research, ensure clear facts, sources, and a systematic organization of information.

Fill In The Blanks:

Question 1. .......... is the major raw material for biogas.
Answer: cow dung
In simple words: Cow dung is the primary natural material used to produce biogas.

🎯 Exam Tip: Remember common raw materials for renewable energy sources.

Question 2. Atomic energy is obtained by using ores of .......... .
Answer: Uranium
In simple words: Uranium ores are used to generate atomic energy.

🎯 Exam Tip: Associate specific elements with their primary energy applications.

Question 3. Biogas generation is mainly based on the principle of .......... .
Answer: Fermentation
In simple words: Biogas is produced through the biological process of fermentation.

🎯 Exam Tip: Understand the basic scientific principles behind common processes like biogas production.

Question 4. Floods can be prevented by ............... .
Answer: Afforestation
In simple words: Planting more trees, or afforestation, helps prevent floods by improving soil water absorption.

🎯 Exam Tip: Connect environmental solutions directly to their respective problems.

Question 5. Coal, petroleum, natural gas are ............... resources.
Answer: non-renewable
In simple words: Coal, petroleum, and natural gas are finite, non-renewable resources.

🎯 Exam Tip: Classify resources correctly as renewable or non-renewable.

Question 6. The total percent of land of world under forest cover is ................ .
Answer: 30%
In simple words: Approximately 30% of the world's land area is covered by forests.

🎯 Exam Tip: Memorize key statistical facts related to natural resources.

Question 7. A naturally occurring substance ............. .
Answer: minerals
In simple words: Minerals are substances that occur naturally in the Earth.

🎯 Exam Tip: Recall the definition of fundamental natural components.

Question 8. Minerals that contain a high proportion of metal are called ............... .
Answer: ore
In simple words: Rocks with a high concentration of extractable metals are called ores.

🎯 Exam Tip: Distinguish between minerals and ores based on metal content.

Question 9. Coal, mineral oil and natural gas are ............... .
Answer: fossil fuel
In simple words: Coal, mineral oil, and natural gas are types of fossil fuels.

🎯 Exam Tip: Group related natural resources under their broader categories.

Question 10. Deposits of common salt are also found in the earth. This salt is called ............... .
Answer: rock salt
In simple words: Common salt deposits found underground are known as rock salt.

🎯 Exam Tip: Be aware of different forms or names for common substances in nature.

Question 11. ............... is the liquid fuel formed by the decomposition of organic substances.
Answer: Mineral oil
In simple words: Mineral oil is a liquid fuel created from decayed organic matter.

🎯 Exam Tip: Link the formation process to the specific type of fuel.

Question 12. The underground mineral oil is extracted through ............... .
Answer: oil wells
In simple words: Mineral oil found beneath the Earth's surface is extracted using oil wells.

🎯 Exam Tip: Identify the methods used for extracting various natural resources.

Question 13. Mineral oil is also known as ............... or ............... .
Answer: petroleum, crude oil
In simple words: Mineral oil is also commonly referred to as petroleum or crude oil.

🎯 Exam Tip: Know alternative names for important natural resources.

Question 14. ............... are the preserved remains of dead organisms in rock.
Answer: Fossil
In simple words: Fossils are the ancient preserved remains of dead organisms found in rock.

🎯 Exam Tip: Understand the definition of geological terms like 'fossil'.

Question 15. Coal can be formed from ............... .
Answer: Fossils
In simple words: Coal is formed from the fossilized remains of ancient plant matter.

🎯 Exam Tip: Recognize the origin of fossil fuels.

Question 16. Impurities of sand and soil in ore are called ............... .
Answer: Gangue
In simple words: The waste materials like sand and soil found in an ore are called gangue.

🎯 Exam Tip: Know the specific terminology used in mineral extraction.

Question 17. Coal mainly contains ............... .
Answer: carbon
In simple words: The primary element in coal is carbon.

🎯 Exam Tip: Identify the main chemical composition of key natural resources.

Question 18. Petroleum is formed from ............... .
Answer: organisms in sea
In simple words: Petroleum originates from ancient marine organisms.

🎯 Exam Tip: Differentiate the origins of different fossil fuels (e.g., coal from land plants, petroleum from marine organisms).

Question 19. Separation of various fractions of petroleum is called ............... .
Answer: Refining
In simple words: The process of separating petroleum into its different components is called refining.

🎯 Exam Tip: Understand the key industrial processes for natural resources.

Question 20. We can obtain minerals from rocks by ................ .
Answer: mining
In simple words: Minerals are extracted from rocks through the process of mining.

🎯 Exam Tip: Know the fundamental method for obtaining minerals.

Question 21. ............... is the most important ore of aluminium
Answer: Bauxite
In simple words: Bauxite is the primary and most important ore from which aluminum is extracted.

🎯 Exam Tip: Connect specific metals with their main ores.

Question 22. is the coal of the highest grade.
Answer: Anthracite
In simple words: Anthracite is known as the highest grade of coal due to its high carbon content and energy output. It burns cleanly with very little ash and smoke.

🎯 Exam Tip: Remember the different grades of coal, especially anthracite, as it's a key example for energy resources.

Question 23. Metals are obtained from their ore by - and .
Answer: extraction, purification
In simple words: Metals are initially taken from their ores through a process called extraction, and then further refined to remove impurities through purification. These two steps are essential to get usable metals.

🎯 Exam Tip: Understanding the two main stages of metal recovery from ores is crucial for explaining mineral processing.

Question 24. is the largest oil and gas research and production company in India.
Answer: ONGC
In simple words: ONGC (Oil and Natural Gas Corporation) is India's leading company for exploring and producing oil and natural gas. It plays a significant role in meeting the country's energy needs.

🎯 Exam Tip: Knowing key national corporations in the natural resources sector demonstrates broader awareness.

Question 25. Natural gas is transformed under high pressure into - and -
Answer: LNG and CNG
In simple words: To make natural gas easier to store and transport, it is compressed into CNG (Compressed Natural Gas) or cooled into a liquid state as LNG (Liquefied Natural Gas). Both forms allow efficient handling of this fuel.

🎯 Exam Tip: Distinguish between CNG and LNG and understand why natural gas is processed into these forms for practical use.

Question 26. The main component of Natural gas is -
Answer: Methane
In simple words: Methane is the primary chemical compound that makes up natural gas, responsible for its energy content. It is a simple hydrocarbon with one carbon atom and four hydrogen atoms.

🎯 Exam Tip: Identify methane as the principal component of natural gas, a fundamental concept in fossil fuels.

Question 27. and are used for adding fragrance in soaps and incense sticks.
Answer: Sandalwood and oil of Encalyptus
In simple words: Sandalwood and eucalyptus oil are natural substances highly valued for their distinct and pleasant aromas. They are commonly used to add fragrance to products like soaps and incense sticks.

🎯 Exam Tip: Provide specific examples of natural resources and their applications, especially in everyday products.

Question 28. is a natural herbal medicine for cough and cold.
Answer: Adulsa
In simple words: Adulsa is a plant traditionally recognized for its medicinal properties, particularly for treating respiratory issues like coughs and colds. It's an example of a natural remedy.

🎯 Exam Tip: Focus on linking specific plants to their traditional medicinal uses to highlight their importance as natural resources.

Answer The Following:

Question 1. What is meant by natural resources?
Answer: 1. We get many substances from nature. 2. They satisfy a variety of our daily needs. Soil, stones, minerals, air, water, plants and animals on the earth are all various kinds of natural resources.
In simple words: Natural resources are all the useful materials and living things that come directly from the Earth, such as soil, water, plants, animals, and minerals, which meet our daily needs. They are found naturally in our environment.

🎯 Exam Tip: Define natural resources clearly by listing examples of both living and non-living components.

Question 2. What are alternative fuels?
Answer: Hydrogen, biofuels, methanol or wood alcohol, ethanol or green alcohol are some of the alternative fuels.
In simple words: Alternative fuels are energy sources used instead of traditional fossil fuels to reduce environmental impact and improve energy sustainability. Examples include hydrogen, biofuels, methanol, and ethanol.

🎯 Exam Tip: List a few diverse examples of alternative fuels to show a comprehensive understanding beyond just one type.

Question 3. What is meant by fuels?
Answer: 1. Fuel is a substance that is used in day-to-day life and burned to generate energy. 2. Fuels such as coal, wood, oil, gas provide energy when burned. 3. Fuels are found in solid, liquid or gaseous state.
In simple words: Fuels are materials that release energy, usually in the form of heat, when they are burned, and they exist in solid, liquid, or gas forms. They are essential for power generation and daily activities.

🎯 Exam Tip: A good answer defines fuel by its primary function (generating energy) and its physical states.

Question 4. Which natural resources do we use as fuels?
Answer: We use coal, mineral oil and natural gas as fuels.
In simple words: The primary natural resources used as fuels are fossil fuels like coal, mineral oil (petroleum), and natural gas, which are burned to produce energy. These are vital for industrial and domestic use.

🎯 Exam Tip: Explicitly name the major fossil fuels (coal, mineral oil, natural gas) when asked about natural resources used as fuels.

Question 5. What is meant by forests?
Answer: An extensive area of land covered by a variety of plants is called a forest. A forest is a natural habitat of plants, animals and microbes.
In simple words: A forest is a large area of land densely covered with various plants, serving as a natural home for many different species of animals and microscopic organisms. They are vital ecosystems supporting biodiversity.

🎯 Exam Tip: Define forests by mentioning their key characteristics: extensive plant cover and role as a natural habitat for diverse life forms.

Question 6. What are the uses of forests?
OR
Write short note on forest and its uses.
Answer: 1. A forest is a natural habitat of plants, animals and microbes. 2. Forest help improve and maintain the quality of environment. 3. Forest helps in prevention of soil-erosion, help to control floods, protects wild life, maintains the balance of atmospheric gases. 4. We get many medicinal plants from forest which help in treatment of various diseases. 5. Examples Adulsa, Bel, Neem, periwinkle, amla tulsi, cinnamon. 6. We also get wood, firewood from trees like teak, mahogani, neem, sababhul. Wood is useful for making furniture, farming implements, in construction work. 7. Forest wealth includes fibres, paper, rubber, gum and aromatic substances. 8. We get fragrant essential oils from lemon grass, vanilla, kewada and eucalyptus. 9. They are used for making soaps, cosmetics and incense sticks. We get various fruits, bulbs, roots, honey, sealing wax, catechu dyes etc. from forest.
In simple words: Forests are crucial for the environment, preventing soil erosion, controlling floods, and maintaining atmospheric balance. They also provide essential resources like wood, medicinal plants, fibers, and aromatic substances for human use.

🎯 Exam Tip: Organize the uses of forests into categories like environmental benefits and direct resources for human consumption to ensure a comprehensive answer.

Question 7. Are minerals to be found in seas and on the seabed as they are found inside the earth?
Answer: Yes, there are very large reserves of tin chromium, phosphates, copper, zinc, iron, lead, manganese, sulphur, uranium etc. in the ocean and seabed.
In simple words: Yes, oceans and seabeds contain vast quantities of various minerals, much like those found on land. These include valuable elements such as tin, copper, iron, and uranium, dissolved in water or accumulated on the ocean floor.

🎯 Exam Tip: Confirm the presence of minerals in oceans and seabeds and provide specific examples to support the statement.

Question 8. How is mineral oil formed?
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र लाखों वर्षों में खनिज तेल और प्राकृतिक गैस के निर्माण की प्रक्रिया को दर्शाता है। इसमें दिखाया गया है कि कैसे मृत समुद्री जीव समय के साथ तलछट से दब जाते हैं, और उच्च दबाव व तापमान के कारण तेल और गैस में परिवर्तित हो जाते हैं, जिन्हें अंततः निकाला जाता है। 1. Mineral oil is the liquid fuel formed by the decomposition of organic substances buried underground. 2. Millions of years ago, bodies of dead sea organisms sank to the bottom of the sea. 3. Layers of soil and sand collected on them. 4. Due to high pressure and temperature the remains of the dead organisms were transformed into mineral oil. 5. The underground mineral oil is extracted through oil wells.
In simple words: Mineral oil is formed over millions of years from the buried remains of dead sea organisms. Under immense pressure and heat underground, these organic remains decompose and transform into crude oil, which is then extracted through wells.

🎯 Exam Tip: Focus on the key factors – dead organisms, burial, high pressure, and temperature – that contribute to the formation of mineral oil.

Use Your Brain Power!

Question 1. Why are all minerals not ores?
Answer: 1. Minerals that contain a high proportion of metal are called ores. 2. Majority of the metals occur in the form of compounds called ores. 3. But all minerals are not ores. 4. Few metals like gold, silver, copper, platinum and bismuth occur in free state in nature. So all minerals are not ores.
In simple words: Not all minerals are considered ores because ores specifically refer to minerals from which metals can be profitably extracted. Some minerals don't contain enough metal, or the metal is too difficult to extract economically, and some metals already exist in their pure, free state.

🎯 Exam Tip: Clearly define "ore" as a mineral from which metal can be profitably extracted, distinguishing it from other minerals.

Question 2. What is meant by metal mineral and non-metal mineral?
Answer: 1. Metal-minerals contain metallic elements in their chemical formula. So they are called metal-minerals, for example, iron, copper, gold, silver etc. 2. They contain metal in raw form. 3. Non-metallic minerals do not contain metal elements in their inorganic chemical formula Example, Clay, Diamond, Dolomite, Gypsum, Mica, Quartz.
In simple words: Metal minerals are those containing metallic elements like iron or copper, often found in raw form. Non-metal minerals, like clay or diamond, do not contain metallic elements in their chemical structure.

🎯 Exam Tip: The key distinction between metallic and non-metallic minerals lies in the presence or absence of metallic elements in their composition.

Question 3. Why is mineral oil called 'liquid gold'?
Answer: Because of its high price and value and its economic need, the mineral oil is called liquid gold. It's reserve is less and demand is more.
In simple words: Mineral oil is referred to as 'liquid gold' because of its high economic value, significant demand, and limited reserves, making it a very precious and expensive resource, similar to gold.

🎯 Exam Tip: Connect the 'liquid gold' metaphor to mineral oil's high value, scarcity, and crucial role in the global economy.

Question 4. Why is coal called black gold?
Answer: 1. Coal is a storehouse of carbon. Coal is used as a fuel, in thermal power plants as well as to run boilers and railway engines. 2. It is used as a fuel for cooking and for baking bricks in kilns on a large scale. 3. The gaseous fuels, producer gas and water gas are obtained from coal. 4. Coal as an energy resource, contributes greatly to industrial development. 5. As coal is black in colour and worth a lot of money just like gold, it is called black gold.
In simple words: Coal is called 'black gold' because, despite its black color, it holds immense economic value as a primary energy source, driving industries and providing fuel for various purposes, much like precious gold.

🎯 Exam Tip: Explain "black gold" by highlighting coal's significant industrial and energy value, linking it to its color and high economic importance.

Question 5. What would happen if underground mineral resources are exhausted?
Answer: 1. Coal, petroleum and other mineral are all non-renewable sources of energy. 2. The reserve is less and demand is more. They would get exhausted one day. 3. If such a situation occurs, we will not get electricity. 4. All our household and industries depend on electricity. 5. Transportation and household items, and food items would become very costly. 6. The survival of human life will be very difficult.
In simple words: If underground mineral resources like coal and petroleum are exhausted, electricity production would halt, crippling industries and households. This would lead to skyrocketing prices for essential goods and services, making human survival incredibly challenging due to lack of energy and resources.

🎯 Exam Tip: Discuss the cascading effects of resource exhaustion, focusing on electricity, industries, cost of living, and overall human survival.

Question 6. Why is natural gas an eco-friendly fuel?
Answer: 1. Natural gas is an important source of energy which is eco-friendly because of its low carbon dioxide emission. 2. When burned it produces 45% less CO2 than coal, 30% less than oil, and about 15% less than wood. 3. It does not produce carbon monoxide, sulphur dioxide or airborne particles all of which are harmful to human and animal health. 4. It is referred as the clean energy source and is fuel for the present century as it does not ' pollute the atmosphere or contribute to global warming.
In simple words: Natural gas is considered eco-friendly because it produces significantly less carbon dioxide than other fossil fuels and does not release harmful pollutants like carbon monoxide or sulfur dioxide when burned. This makes it a cleaner energy source that contributes less to air pollution and global warming.

🎯 Exam Tip: Highlight the lower emissions of CO2 and absence of harmful pollutants as primary reasons for natural gas being an eco-friendly fuel.

Question 7. What useful things will we have to do without if rubber is no longer available?
Answer: 1. Rubber has played a largely hidden role in global environment history for more than 150 years. 2. In industries, rubber is needed to connect and protect all moving parts of machines. 3. Native people used rubber for rubber boots. 4. Household uses rubber in everything viz dish washing gloves, toys, jar seals, tyres in vehicles. 5. Welcome mat at the door, Boots, raincoats, mattress cushions, earplugs, hot water bottles, surgical tubing and gloves, in labs, birth control device. 6. In schools rubber bands, erasers, mouse pads, key board, rolling chair wheels. Head phone pads, rubber stamps are useful items used in schools and offices.
In simple words: Without rubber, industries would struggle to protect machinery, and many everyday items like tires, gloves, seals, and various household products would no longer exist. Essential items in schools and offices, such as erasers and rubber stamps, would also be absent.

🎯 Exam Tip: Provide a diverse list of applications, from industrial to everyday items, to show the extensive impact of rubber's absence.

Question 8. What are the adverse effects of clearing of forest or cutting down trees?
Answer: 1. Clearing of forest is also called Deforestation. 2. Removal or cutting down of trees has resulted in damage to habitat, biodiversity loss and aridity. 3. If has adverse impacts on concentration of atmospheric carbon dioxide. (Trees use up carbon dioxide from the atmosphere for the process of photosynthesis.) 4. Deforestation is a main contributor to global warming. Major cause of enhanced greenhouse effect. Deforestation cause carbon dioxide to linger in the atmosphere. 5. Deforestation reduced the content of water in the soil and ground water and atmospheric moisture, because trees extract ground water through the roots and release it into the atmosphere. 6. When a part of forest is removed the trees no longer transpire this water, resulting in much drier climate. 7. Due to deforestation soil erosion and flooding, landslide problems occur. 8. Deforestation results in decline in biodiversity, on a natural global scale is known to cause the extinction of many species. 9. Forest is habitat for wild life, and many medicinal plants. If forests are removed it will affect wild life and also we will not get medicinal plants.
In simple words: Clearing forests, known as deforestation, leads to significant environmental problems including habitat destruction, loss of biodiversity, and drier climates due to reduced transpiration. It also increases atmospheric carbon dioxide, contributing to global warming, and causes soil erosion and flooding.

🎯 Exam Tip: Focus on the interconnected environmental consequences of deforestation, such as climate change, biodiversity loss, and soil degradation.

Find Out:

Question 1. How did the various ages of the prehistoric period get their names on the basis of the uses of metals.
Answer: 1. The three-age system in history archaeology, and physical anthropology is a methodological concept adopted during the 19th century by which artifacts and events of late prehistory and early history could be ordered into a recognizable chronology. 2. Initially developed by C. J. Thomson, director of the Royal Museum of Nordic Antiquities, Copenhagen - as a means to classify the museum's collection according to whether the artifacts were made of stone, bronze or iron. 3. Depending-upon the use of stone, bronze, iron, that period was known as stone age, bronze age, and iron age, respectively.
In simple words: The prehistoric period is divided into ages like the Stone Age, Bronze Age, and Iron Age, based on the primary material used for tools and weapons during those times. This system, developed by C. J. Thomson, helps archaeologists categorize historical periods based on technological advancements.

🎯 Exam Tip: Explain the 'Three-Age System' by linking each age (Stone, Bronze, Iron) directly to the dominant material used for tools during that era.

Answer The Following:

Question 1. Write down the difference between Metal minerals and Non-metallic minerals.
Answer:

In simple words: Metal minerals contain metal elements in their raw form, are typically hard, shiny, and found in igneous rocks, like iron and copper. Non-metallic minerals lack metallic elements, are often less hard or shiny, and are usually found in sedimentary rocks, such as salt and clay.

🎯 Exam Tip: When differentiating, ensure you provide clear comparative points for composition, physical properties, geological association, and specific examples for both types of minerals.

Question 2. Write down the different types of coal.
Answer: Peat, lignite (brown coal), bituminous coal and anthracite are various types of coal. Anthracite is the coal of the highest grade.
In simple words: Coal exists in several types, ranging from peat, which is the earliest stage, to lignite (brown coal), then bituminous coal, and finally anthracite, which is the highest quality. These types differ in carbon content and energy output.

🎯 Exam Tip: List the types of coal in increasing order of carbon content and energy value, highlighting anthracite as the highest grade.

Question 3. Write down the characteristics of Compressed Natural Gas.
Answer: Characteristics of CNG: 1. Catches fire easily. 2. No solid waste remains after combustion. 3. Carbon dioxide and water are formed in small quantities. 4. Other pollutants are not produced. 5. Can be transported easily. 6. Combustion can be controlled easily.
In simple words: CNG (Compressed Natural Gas) is a highly flammable fuel that burns cleanly, leaving no solid waste and producing minimal carbon dioxide and water vapor, with no other pollutants. It is also easy to transport and its combustion can be precisely controlled.

🎯 Exam Tip: Focus on the clean-burning, environmental, and practical advantages (transport, control) of CNG as key characteristics.

Observe The Pictures And Answer The Question.

ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र खनिज तेल और प्राकृतिक गैस के निर्माण की प्रक्रिया को तीन चरणों में दिखाता है: लाखों साल पहले मृत समुद्री जीवों का समुद्र तल में दबना, हजारों साल पहले उन पर तलछट की परतें जमना, और वर्तमान में दबाव व गर्मी से तेल व गैस का बनना और उनका निष्कर्षण।

Question a. What is the process shown in the given picture?
Answer: The process shown is formation of mineral oil and natural gas.
In simple words: The picture illustrates the geological process where organic matter is transformed over millions of years into mineral oil and natural gas deep within the Earth's crust.

🎯 Exam Tip: Identify the process accurately as the formation of mineral oil and natural gas, indicating an understanding of fossil fuel creation.

Question b. Explain the process.
Answer: 1. Mineral oil is the liquid fuel formed by the decomposition of organic substances buried underground. 2. Millions of years ago, bodies of dead sea organisms sank to the bottom of the sea. 3. Layers of soil and sand collected on them. 4. Due to high pressure and temperature the remains of the dead organisms were transformed into mineral oil. 5. The underground mineral oil is extracted through oil wells.
In simple words: The process begins with dead sea organisms sinking to the seabed, which are then covered by layers of soil and sand. Over millions of years, intense pressure and heat transform these organic remains into mineral oil, which is later extracted from underground reservoirs using oil wells.

🎯 Exam Tip: Clearly outline the sequential steps of mineral oil formation, from organic deposition to transformation and extraction.

Question c. What are the gaseous substances formed in the above process?
Answer: Natural gas is also formed along with mineral oil. It contains methane, ethane, propane and butane gases.
In simple words: Alongside mineral oil, natural gas is also produced during this process, primarily consisting of methane, with smaller amounts of ethane, propane, and butane.

🎯 Exam Tip: Identify natural gas as the primary gaseous product and list its main components like methane, ethane, propane, and butane.

Question d. When the products of the process is refined, what other components are produced?
Answer: When mineral oil is refined by fractional distillation products produced are petrol, diesel, kerosene, naphtha lubricating oil, tar, etc.
In simple words: When crude mineral oil is refined through fractional distillation, it separates into various useful components such as petrol, diesel, kerosene, naphtha, lubricating oil, and tar. Each component has different uses based on its boiling point.

🎯 Exam Tip: Enumerate the key products obtained from the fractional distillation of mineral oil, demonstrating knowledge of petroleum refining.