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Friday, 11 November 2011

CLASS X CHAPTER 5 MINERALS AND ENERGY RESOURCES PART I

1 What is a mineral?
Ans. Minerals are a “homogenous, naturally occurring substance with a definable internal structure.” Minerals are found in varied forms in nature, ranging from the hardest diamond to the softest talc
2. What  are the basis of classification of  minerals by the geologists.
Ans. Geologists use the properties such as colours, hardness, crystal forms, lustre and density to classify the minerals.
3  What are ores?
Ans. Minerals found in their raw form is called as “ores”. That means ore is an accumulation of any mineral mixed with other elements.

4  Mention any two factors which determine the  extraction of minerals.
Ans. Extraction of any mineral depends upon its  commercial viability
Commercial viability depends on the following factors:
1. Concentration: The mineral content of the ore must be in sufficient concentration to make its extraction commercially viable.
2. Ease of extraction: The type of formation or structure in which they are found determines the relative ease with which mineral ores may be mined. This also determines the cost of extraction.
3. Market and demand of mineral makes some minerals more commercially viable.

5 Explain the main types of formations in which minerals occur.
Ans. Minerals generally occur in the following  forms:
(i) In igneous and metamorphic rocks minerals may occur in the cracks, crevices, faults or joints. The smaller occurrences are called veins and the larger are called lodes. In most cases, they are formed when minerals in liquid/ molten and gaseous forms are forced upward through cavities towards the earth’s surface. They cool and solidify as they rise. Major metallic minerals like tin, copper, zinc and lead etc. are obtained from veins and lodes.
(ii) In sedimentary rocks a number of minerals occur in beds or layers. They have been formed as a result of deposition, accumulation and concentration in horizontal strata. Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure. Another group of sedimentary minerals include gypsum, potash salt and sodium salt. These are formed as a result of evaporation especially in arid regions.
(iii) Another mode of formation involves the decomposition of surface rocks, and the removal of soluble constituents, leaving a residual mass of weathered material containing ores. Bauxite is formed this way.
(iv) Certain minerals may occur as alluvial deposits in sands of valley floors and the base of hills. These deposits are called ‘placer deposits’ and generally contain minerals, which are not corroded by water. Gold, silver, tin and platinum are most important among such minerals.
(v) The ocean waters contain vast quantities of minerals, but most of these are too widely diffused to be of economic significance. However, common salt, magnesium and bromine are largely derived from ocean waters. The ocean beds, too, are rich in manganese nodules.
6 What is Rat-Hole Mining?
Ans. In the tribal areas of the north-east India, minerals are owned by individuals or communities. In Meghalaya, there are large deposits of coal, iron ore, limestone and dolomite etc. Mining in these areas is done by family member in the form of a long narrow tunnel, known as ‘Rat hole’ mining.
7 Which are the two types of mining

1. Surface mining  -Which includes An open pit mine and quarrying
2. Sub-surface mining (An underground mine with shafts)

8  Describe the general distribution of mineral resources in India.
Ans. India has rich and a large variety of minerals.
a. Peninsular rocks contain most of the reserves of coal, metallic minerals, mica and many other non-metallic minerals.
b. Sedimentary rocks on the western and eastern coasts, in Gujarat and Assam have most of the petroleum deposits.
c. The rock systems of the Rajasthan have reserves of many non-ferrous minerals.
d. The vast alluvial plains of north India are almost without minerals.
e. These variations exist largely because of the differences in the geological structure, processes and time involved in the formation of minerals.

9 Give reason for the variation in the uneven distribution of minerals in India.

The variation in the uneven distribution of minerals in India. exist largely because of the differences in the geological structure, processes and time involved in the formation of minerals
Which are the two types of Iron  ore found in India ?
Types of iron ore in India:
a. Magnetite is the finest iron ore with a very high content of iron up to 70 percent. It has excellent magnetic qualities.
b. Hematite ore has slightly lower iron content than magnetite (50-60 per cent). It is largest used type of iron ore in Indian industries

10 Describe the distribution of Iron ore in India
Distribution of iron ore:
a. The five largest iron producing states are Karnataka, Orissa, Chhattisgarh, Goa and Jharkhand.
b. Iron ore is found in the four belts
i. Orissa-Jharkhand belt: high grade hematite ore is found. Important mines are Badampahar and Singbhum mines.
ii. Durg-Bastar belt lies in Chhattisgarh and Maharashtra: Very high grade hematite are found. Famous mine are Bailadila which produces iron best suited for steel making.
iii. Bellary-Chitradurga-Chikmaglur-Tumkur belt in Karnataka has large reserves of iron ore.
iv. Maharashtra-Goa belt includes the state of Goa and Ratnagiri district of Maharashtra.

11 Name the mines  and the ports through whichiron-ore is exported

Export of iron ore:
a. Hematite ore from Bailadila mines are exported to Japan and South Korea via Vishakapatnam port.
b. The Kudremukh mines located in the Western Ghats of Karnataka are a 100 per cent export unit. Kudremukh deposits are known to be one of the largest in the world. The ore is transported as slurry through a pipeline to a port near Mangalore.
c. Iron ore from Goa is not of very high quality, yet they are exported through Marmagao port.

12  What are the uses of Manganese ?
Uses of Manganese:
a. It is mainly used in the manufacturing of steel and ferro-manganese alloy.
b. Nearly 10 kg of manganese is required to manufacture one tonne of steel.
c. It is also used in manufacturing bleaching powder, insecticides and paints.
13  Name the leading producer of manganese in India
Orissa is the largest producer of manganese in India.

14. What are the uses of copper:
  1. Copper is malleable, ductile and a good conductor therefore it is mainly used in electrical cables, electronics and chemical industries
 15 Which is the leading producer of Copper in India ? 
 Madhya Pradesh is the largest producer of copper in India

16. Describe the distribution of copper in India
Distribution of copper:
a. Madhya Pradesh is the largest producer of copper in India. The Balaghat mines
in Madhya Pradesh produce 52 per cent of India’s copper.
b. Rajasthan is the second largest producer of copper. The Khetri mines in Rajasthan are famous.
c. The Singbhum district of Jharkhand is also a leading producer of copper.
d. India is critically deficient in the reserve and production of copper.
17 What are the uses of Bauxite:
a. Bauxite is the ore which contain aluminium. It is from bauxite, a clay-like substance that alumina and later aluminium is obtained.
b. Aluminium is an important metal because it has strength of iron; it is extremely light, good conductor of electricity and great malleability.
c. It is used in electrical industries, aircraft manufacturing industries, utensils making, etc.
18 Describe the Distribution of Bauxite:
a. Orissa, Gujarat, Jharkhand and Maharashtra are the important bauxite producing states of India.
b. Orissa is the largest bauxite producing state in India with 45 per cent of the country’s total production in 2000-01. Panchpatmali deposits in Koraput district are the most important bauxite deposits in the state.
19 What are the uses of mica:
a. Mica has excellent di-electric strength, low power loss factor, insulating properties and resistance to high voltage.
b. Therefore, mica is one of the largest used mineral in electric and electronic industries.
20 Describe the Distribution of Mica:
a. Jharkhand is the leading producer of mica in India.
b. Mica deposits are found in the northern edge of the Chota Nagpur plateau.
c. It is also found in Rajasthan, the major mica producing area is around Ajmer.
d. Nellore mica belt of Andhra Pradesh is also an important producer in the country.
21 What are the uses of Limestone
 Limestone is the basic raw material for the cement industry and essential for smelting iron ore in the blast furnace.

22 Describe the distribution of limestone in India
a . Limestone is found in rocks composed of calcium carbonates or calcium and magnesium carbonates.
b. It is found in sedimentary rocks of most geological formations.
c. Andhra Pradesh, Rajasthan, Gujarat, Tamil Nadu are the major limestone producing states of India.
23 What are the impacts of mining on the health of the miners and the environment?
Ans. Mining can become a killer industry. Its effects are:
a. The dust and noxious fumes inhaled by miners make them vulnerable to pulmonary diseases.
b. The risk of collapsing mine roofs, inundation and fires in coalmines are a constant threat to miners.
c. The water sources in the region get contaminated due to mining.
d. Dumping of waste and slurry leads to degradation of land, soil, and increase in stream and river pollution

24  Explain why the conservation of minerals is necessary in India.
Ans. Minerals are important for every country for its development. They need to be conserved.
a. Industry and agriculture depend upon mineral deposits.
b. Minerals are in insufficient quantities, just one per cent of the earth’s crust.
c. We are rapidly consuming mineral resources that required millions of years to be created and concentrated.
d. The natural rate of replenishment is very small in comparison to the present rates of consumption.
e. Mineral resources are non-renewable resources.
f. Rich mineral deposits in our country are short-lived.
g. Continued extraction of ores leads to increasing costs as mineral extraction.
25 Mention different steps or ways of conserving our mineral resources.
Ans. Minerals has to be conserved for the future generations.
a. A concerted effort has to be made in order to use our mineral resources in a planned and sustainable manner.
b. Improved technologies need to be constantly evolved to allow use of low grade ores at low costs.
c. Recycling of metals, using scrap metals and other substitutes are steps in conserving our mineral resources for the future.


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