NOTES
- Minerals are naturally occurring substances that have a definite chemical composition.
- Minerals are formed in different types of geological environments, under varying conditions.
- Minerals can be identified on the basis of their physical properties such as colour, density, hardness and chemical property such as solubility.
- Minerals are distributed in rocks and sea bed also.
- Tropical regions are very rich in terms of mineral resources.
Types of Minerals:
- On the basis of composition, minerals are classified into metallic and non-metallic types.
- Metallic, minerals contain metals in raw form.
- Metals are hard substances that conduct heat and electricity and have lustre or shine. For example, iron ore and bauxite.
- Metallic minerals are of two types: (a) Ferrous and (b) Non-ferrous.
- Ferrous minerals contain iron ore, manganese and chromites. Most of the Iron and steel industries and heavy industries depends on this mineral.
- Non-ferrous minerals do not contain iron but may contain some other metals like gold, silver, copper or lead.
- Non-metallic minerals do not contain metals. For example, limestone, mica, gypsum, coal and petroleum.
- Mining, drilling and quarrying are the three extraction methods of minerals.
- Mining is the process of taking out minerals from rocks buried under the earth’s surface.
- The process of mining includes two methods: (a) Open cast mining, (b) Shaft mining
- Deep wells are bored to take minerals out and this process is called drilling.
- In the process of quarrying, minerals that lie near the surface are simply dug out.
- Mineral based industries are the backbone of industrial development of a naion.
- Mining needs cheep labour and resources to extract it off.
Distribution of Minerals:
- Minerals are found in igneous rock, metamorphic rocks and sedimentary rocks.
- Iron ore, nickel, copper minerals are found in igneous and metamorphic rocks.
- Limestone is found in sedimentary rocks.
- Plateau region of India such as Daccan and chota nagpur plateau provides the rich level of mineral distribution.
Uses of Minerals:
- Some minerals which are usually hard are used as gems for making jewellery.
- Copper is used in almost everything from coins to pipes.
- Silicon is used in almost everything from coins to pipes.
- Silicon is used in the computer industry which is obtained from quartz.
- Aluminium is used in automobile, airplanes, bottling industry, building and in kitchen cookware.
- Mica is used to make electrical appliances and glass making industries.
- Iron and steel is used in every indurstry.
Distribution of Minerals in India:
- Iron: Jharkhand, Odisha and Chattisgarh
- Bauxite: Jharkhand, Odisha and Chattisgarh
- Mica: India is the leading producer of mica in the world. Jharkhand, Bihar, Andhra Pradesh are major producing states.
- Gold: Kolar in Karnataka
Conservation of Minerals:
- Minerals are the non-renewable resources.
- It is necessary to reduce wastage in process of mining.
- Recycling of metals is the way to conserve mineral resources.
- over exploitation is harmful for environment as well.
· Power Resources:
- Power resources are of two types: (a) Conventional Resources, (b) Non-conventional Resources
- We need power resources for industry,domastic use, agriculture, transport, communication and defence.
Conventional Sources of Minerals:
- The energy resources which have been in common use for a long time are known as conventional sources.
- Firewood and fossil fuels are two main conventional energy sources.
- Fossil fuels comprises of Coal( known as burried sunshine), Patroleum (known as black gold), Natural Gas and Hydroelectricity.
Non-Conventional Sources of Minerals:
- Non-conventional sources of energy are renewable in nature.
- Solar energy, wind energy, tidal energy, etc. are the examples of non-conventional sources of energy.
- They are more expensive as it needs technological upgradation.
- India has a great potential for Solar energy.
EXERCISE
1. Answer the following questions.
(i) Name any three common minerals used by you every day.
Ans: The three common minerals used every day are Salt, Gold and Copper.
(ii) What is an ore? Where are the ores of metallic minerals generally located?
Ans: Rocks from which minerals are obtained are known as ores. For any material to be called ore of any mineral, it must contain a minimum adequate quantity of that mineral so that it can be extracted profitably.
The ores of metallic minerals are generally located in igneous rocks and metamorphic rocks.
(iii) Name two regions rich in natural gas resources.
Ans: The two regions rich in natural gas resources are Russia and Norway.
(iv) Which sources of energy would you suggest for rural areas (b) coastal areas (c) Arid regions?
Ans:
| Kind of Regions | Suggested sources of energy | |
| A. | Rural areas | Biogas energy. |
| B. | Coastal area | Hydel and tidal energy. |
| C. | Arid regions | Wind and solar energy. |
(v) Give five ways in which you can save energy at home.
Ans: Five ways in which energy can be saved at home:
(i) Switching off lights, fans and other electrical appliances when not in use
(ii) By seeing to it that electrical devices are operating efficiently; for example, defrosting refrigerator regularly and not keeping the refrigerator door open for longer than necessary
(iii) Using energy-efficient devices such as fluorescent bulbs and tubes
(iv) Using energy efficiently while cooking; for example, keeping the lids closed, while cooking
(v) Unplugging electrical devices when not in use prevents leakage of electricity; thus saving energy.
2. Tick the correct Answer.
(i) Which one of the following is NOT a characteristic of minerals?
(a) They are created by natural processes.
(b) They have a definite chemical composition.
(c) They are inexhaustible.
(d) Their distribution is uneven.
Ans: (c) They are inexhaustible.
(ii) Which one of the following is NOT a producer of mica?
(a) Jharkhand (b) Karnataka (c) Rajasthan (d) Andhra Pradesh
Ans: (b) Karnataka
(iii) Which one of the following is a leading producer of copper in the world?
(a) Bolivia (b) Ghana (c) Chile (d) Zimbabwe
Ans: (c) Chile.
(iv) Which one of the following practices will NOT conserve LPG in your kitchen?
(a) Soaking the dal for some time before cooking it.
(b) Cooking food in a pressure cooker.
(c) Keeping the vegetables chopped before lighting the gas for cooking.
(d) Cooking food in an open pan kept on low flame.
Ans: (d) Cooking food in an open pan kept on low flame.
3. Give reasons.
(i) Environmental aspects must be carefully looked into before building huge dams.
Ans: Environmental aspects must be carefully looked into before building huge dams because of the following reasons -
- Dams create an imbalance in the earth’s equilibrium.
- Deforestation leads to environmental pollution.
- People become displaced.
- Cities/ villages/ towns may require shifting causing a lot of hardships for the people.
- Flood threats loom large.
- Earthquake threats
- Silting of lakes is a problem
(ii) Most industries are concentrated around coal mines.
Ans: Coal is used as a source of energy and power and also as a raw material in most of the industries. Hence most industries are concentrated around coal mines for the purpose of saving cost of transportation of coal (cost effectiveness).
(iii) Petroleum is referred to as “black gold”.
Ans: Petroleum is referred to as “black gold” because it is black in colour in the crude form and its derivatives are extremely valuable as petroleum itself. Today it is almost inevitable in our day-to-day life. A variety of products like – kerosene, diesel, petrol, wax, plastics, lubricants etc. are produced from these mineral resources.
(iv) Quarrying can become a major environmental concern.
Ans: Quarrying can become a major environmental concern because of the following reasons:
- It may destroy the humus of soil which is much required for the growth of plants and crops.
- It produces a lot of noise pollution due to use of explosives at times in order to break the huge chunks of rocks.
- In the process of quarrying lot of dust is generated which causes air pollution and also occupational hazards.
- Blasting done for the purpose of quarrying generate vibration which damages the nearby buildings, dams or any other similar structure.
4. Distinguish between the followings.
(i) Conventional and Non-conventional sources of energy
| Conventional sources of energy | Non-conventional sources of energy | |
| 1. | Conventional Sources of Energy have been in common use for a long time. | Non-Conventional Sources of Energy are not commonly used. |
| 2. | Conventional Sources of Energy are exhaustible except water. | Non-conventional Sources of Energy are inexhaustible. |
| 3. | Conventional Sources of Energy cause pollution. | Non-conventional Sources of Energy are pollution free |
| 4. | Firewood, coal are examples of Conventional sources of energy | Solar energy, nuclear energy are examples of Non Conventional sources of energy |
(ii) Biogas and natural gas
| Biogas | Natural gas | |
| 1. | It is produced by using organic matter like dead plants, animal dung, kitchen waste, etc. | It is found along with petroleum and gets released when crude oil is brought to the surface. |
| 2. | It is a non-conventional source of energy. | It is a conventional source of energy. |
| 3. | It is Is easily available, especially in rural areas. | Very few countries have sufficient natural gas reserves of their own. It is not easily available; |
| 4. | It pollutes the environment since it releases carbon-dioxide in the air. | It is a cleaner fuel than many others. |
| 5. | It is used for domestic purposes like cooking and lighting. | It is used as a domestic fuel as well as an industrial fuel. |
(iii) Ferrous and Non-ferrous minerals
| Ferrous mineral | Non-ferrous mineral | |
| 1. | Ferrous mineral is a metallic mineral that contains iron. | Non - Ferrous mineral is a metallic mineral that does not contain iron. |
| 2. | Iron ore and manganese are Ferrous minerals | Gold, silver are examples of Non-ferrous minerals |
(iv) Metallic and Non-metallic minerals
| Metallic mineral | Non-metallic mineral | |
| 1. | A mineral containing metal in raw form are Metallic mineral. | A mineral not containing metal are Non-metallic mineral . |
| 2. | Bauxite, iron ore are Metallic mineral | Limestone, gypsum are Non-metallic mineral |