Samacheer Class 7 Social Science - Resources

1. China is the largest producer of hydroelectricity in the world, utilizing its abundant water resources and river systems to generate significant amounts of electrical power. 2. Iron ores are found at Kanjamalai in Tamil Nadu, which is an important source of this valuable metallic mineral. 3. Aluminum is produced from bauxite ore through an industrial refining process, making bauxite the primary source of this widely used metal. 4. Manganese is used in making electrical batteries and serves various other industrial purposes due to its chemical properties. 5. Petroleum and its derivatives are collectively called black gold because of their immense economic value and importance to modern economies and industries worldwide.

Solar
2. Hydroelectricity is generated from…………………water.
moving
3. ………………..resources that are once consumed and cannot be replaced.
Non – renewable
4. ………………..is the world’s number one country in the production of copper.
Chile5. ………………..is a rare and precious metal.
Gold
6. …………….. field is one of the deepest mines of the world located in India.
Kolar Gold
7. ………………… is the world’s leading bauxite producer.
Australia
8. …………………is the world’s leading producer of manganese.
South Africa
9. …………………and…………………are the common ores of mica.
Muscovite and Biotite10. ………………… is the world’s top producer of Mica.
China
11. Fossil fuels are formed from…………………
hydro carbon
12. ………………..in china is the largest hydroelectricity project in the world.
Three Gorges Dam
13. Tehri Dam is situated in ………………… in India.
Uttarakhand
14. The leading coal producers of the world is …………………
Arts:
China
15. ……………………..energy is not harmful to the environment
Solar

Iron is a highly versatile and widely used metal, primarily known for its role in making steel. Steel, an alloy of iron and carbon, is indispensable across numerous industries due to its strength, durability, and relatively low cost. In engineering applications, iron and steel are crucial for the construction of heavy machinery, machine tools, and a vast array of vehicles including automobiles, trains, and large ships. Furthermore, they form the structural backbone of modern infrastructure, being used extensively in the construction of buildings, bridges, and other large-scale civil engineering projects. Its magnetic properties also make it useful in electrical applications and various manufacturing processes.

Duralumin is a notable alloy of aluminum, highly valued for its combination of strength, hardness, and lightweight properties. These characteristics make it particularly suitable for applications where both structural integrity and reduced weight are critical, such as in aircraft construction. It is produced by adding small quantities of other metals like copper, magnesium, and manganese to pure aluminum. This alloying process significantly enhances the mechanical properties of aluminum, resulting in a material that is superior in strength and durability compared to pure aluminum, while still retaining its low density. Its widespread use in aerospace engineering highlights its importance as an advanced material.

Biotic resources are found in the biosphere and are obtained from living and organic materials. They include all living organisms and their products. Biotic resources depend on abiotic resources for their survival and growth. Examples of biotic resources are plants, trees, animals, birds, fish, microorganisms, and all other living things. Abiotic resources, on the other hand, are the non-living parts of an environment. These resources do not depend on biotic resources for their existence. Abiotic resources include sunlight, temperature, water, soil, air, minerals, and rocks. Together, biotic and abiotic resources form the complete natural environment and are interdependent in maintaining ecological balance.

Renewable resources are those that can be used again and again throughout their life without being completely depleted. These resources are present in unlimited or abundant quantities and can be replenished naturally. Renewable resources are generally pollution-free and environmentally sustainable. Examples of renewable resources include solar energy, wind energy, hydropower, geothermal energy, and biomass. Non-renewable resources, in contrast, cannot be used again and again as they are limited in quantity and can be depleted one day. These resources are present in finite quantities only and take millions of years to form. Non-renewable resources are not pollution-free and their extraction and use often cause environmental damage. Examples of non-renewable resources include fossil fuels such as coal, petroleum, and natural gas, as well as metallic minerals like iron, copper, gold, and silver. The distinction between these two types is crucial for understanding sustainable resource management.

Metallic resources are types of resources that are composed of metals and contain metallic elements. These are hard substances with high density and are excellent conductors of heat and electricity. Metallic resources have properties such as malleability, ductility, and luster, which make them valuable for industrial applications. Examples of metallic resources include iron, copper, gold, bauxite, silver, manganese, and tin. These metals are essential for manufacturing machinery, tools, vehicles, buildings, and various industrial products. Non-metallic resources, conversely, are resources that do not comprise metals and lack metallic properties. These are not hard substances in the same way as metals and are generally poor conductors of heat and electricity. Non-metallic resources include minerals such as mica, limestone, gypsum, dolomite, phosphate, coal, and gemstones. These resources are used in construction, agriculture, chemical industries, and various other applications. The classification of resources into metallic and non-metallic helps in understanding their properties and appropriate uses in different industries.

Aluminium is a light in weight, tough, and relatively cheaper metal compared to many other metals, which makes it a popular choice for construction and industrial purposes. Due to these properties, aluminium has a wide range of applications across various sectors. It is extensively used in the construction of aircraft, ships, automobiles, railway coaches, and other transportation vehicles where weight reduction is important for fuel efficiency and performance. Additionally, aluminium is used in the manufacture of electrical cables, kitchen utensils, packaging materials, and building materials such as window frames and roofing sheets. Its resistance to corrosion makes it suitable for outdoor applications. The combination of its lightweight nature, durability, affordability, and versatility in applications makes aluminium one of the most widely used metals in modern industry and construction, far exceeding the utility of many other metals.

Water is considered a great source of energy because it can be harnessed to produce hydroelectric power on a large scale. Hydroelectricity is generated by utilizing the kinetic energy of moving water with high velocity and water falling from great heights. This flowing or falling water is directed through turbines, which rotate and drive dynamos to generate electricity. The process is clean and does not produce harmful emissions or pollutants. Water is a renewable resource that is continuously replenished through the water cycle, making it a sustainable source of energy. Many countries have constructed dams and hydroelectric power plants on rivers to tap this energy source. The power generated from water depends on the volume of water and the height from which it falls, both of which can be substantial in hilly and mountainous regions. This makes water an important and reliable source of energy for meeting the electricity demands of modern society.

Wind power is considered clean energy because wind turbines do not produce any harmful emissions, pollutants, or greenhouse gases during the generation of electricity. Unlike fossil fuel-based power plants that burn coal, oil, or natural gas and release carbon dioxide and other toxic substances into the atmosphere, wind energy is completely environmentally friendly. Wind is a renewable resource that is naturally replenished and will not deplete over time. In recent years, wind energy has emerged as one of the most economical and practical renewable energy technologies available. Wind turbines convert the kinetic energy of wind into electrical energy through rotating blades connected to generators. Wind farms can be established in areas with consistent wind patterns, such as coastal regions and elevated plains. The maintenance costs of wind turbines are relatively low compared to other energy sources. As concerns about climate change and environmental pollution increase globally, wind power plays an increasingly important role in sustainable energy production and reducing dependence on non-renewable fossil fuels.

Solar energy:
The sun produces energy in the form of heat and light. Solar energy is not harmful to the environment.
Photovoltaic devices or solar cells, directly convert solar energy into electricity.
India, China, Japan, Italy, and the States of America are major utilizers of solar energy in the world.
Hydropower:
Hydroelectricity power is the cheapest and most versatile source of energy out of all the know energy. Hydroelectric power is a renewable resource.
China, Canada, Brazil, the United States of America, Russia, India, Norway, and Japan are some countries producing hydroelectricity. China is the largest producer of hydroelectricity.
Wind energy :
Wind power is clean energy since wind turbines do not produce any emission.
In recent years, wind energy has become one of the most economical and renewable energy technologies.
Major wind energy-producing countries are United States, China, Germany, Spain, India, United Kingdom, Canada and Brazil.

Non-metallic resources:
Non-metallic resources can be described as the resources that do not comprise of metals.
These are not hard substances and are not good conductors of heat and electricity.
Examples of non-metallic resources are mica, limestone, gypsum, dolomite, phosphate, etc.
Mica:
Muscovite and Biotite are the common ores of Mica.
It is one of the indispensable minerals used in the electrical and electronics industry.
In powder form, it is used for making lubricating oils and decorative wallpapers.
Limestone:
Limestone is a sedimentary rock, composed mainly by skeletal fragments of marine organisms such as coral, foraminifera and molluscs.
About 10% of sedimentary rocks are limestones. Mostly limestone is made into crushed stone and used as a construction material.
It is used for facing stone, floor tiles, stair treads, windows sills, and many other purposes.
Crushed limestone is used in smelting and other metal refining process. Portland cement is made from limestone.

Fossil fuel resources:
Fossil fuel resources are normally formed from the remains of dead plants and animals.
They are often referred to as fossil fuels and are formed from hydrocarbon.
Coal:
This is the most abundantly found fossil fuel that forms when dead plant matter is converted into peat.
It is used as a domestic fuel, in industries such as iron and steel, steam engines to generate electricity.
Petroleum:
Petroleum is found between the layers of rocks and is drilled from oil fields located in Offshore and coastal areas.
Petroleum and its derivatives are called Black Gold as they are very valuable.
Natural gas:
Natural gas is found with petroleum deposits and is released when crude oil is brought to the surface.
It can be used as a domestic and industrial fuel.

Across: 2. The leading coal producers of the world are countries like China, which is the largest producer, followed by India and the United States. Coal is a fossil fuel widely used for electricity generation and industrial processes. 4. Water is considered a great source of energy, especially in the form of hydroelectricity, where the kinetic energy of flowing water is converted into electrical energy. It is a renewable and clean energy source. 5. Silver is a precious metal, similar to gold, known for its luster, malleability, and excellent electrical conductivity. It is used in jewelry, coinage, and various industrial applications. 6. Mica is a mineral widely used as an insulating material in the electrical industry due to its excellent dielectric properties and resistance to heat. Down: 1. Manganese is a metal used in making electrical batteries, particularly in alkaline and zinc-carbon batteries, where it acts as a cathode material. It is also important in steel production. 2. Copper is a good conductor of heat and electricity, making it essential for electrical wiring, plumbing, and various electronic components. It is also corrosion-resistant. 3. Karnataka is the largest producer of gold in India, with the Kolar Gold Fields being historically significant. Gold is a precious metal used for jewelry, investment, and industrial purposes. 5. The Sun produces energy in the form of heat and light through nuclear fusion. This solar energy is a renewable resource that can be harnessed for electricity generation, heating, and lighting.