Ans)

1. In igneous and metamorphic rocks, minerals may occur in the cracks, (NCERT) crevices, faults or joints.
2. The smaller occurrences are called veins and the larger are called lodes.
3. In most cases, they are formed when minerals in liquid or molten and gaseous forms are forced upward through cavities towards the earth’s surface and cool and solidify as they rise.
4. Major metallic minerals like tin, copper, zinc and lead etc. are obtained from veins and lodes.

Ans) Minerals are the unique gifts of nature. They, take million years to form. They are finite. Human is exploiting the nature seamlessly for the sake of development. It reduced the quantity of minerals dramatically. Its bad effects can be seen in future. The competition of exploiting the previous and useful minerals reached to such extent that one nation do not hesitate to invade other for obtaining these resources. Indiscipline exploitation of minerals imbalance the nature and excessive use of them leads to environmental pollution. Therefore it is essential to conserve minerals for their use by future generation.

Ans) Ferrous Minerals- Ferrous minerals account for about three-fourth of the total value of the production of metallic minerals. They provide a strong base for the development of metallurgical industries. India exports substantial quantities of ferrous minerals after meeting her internal demands, such as iron ore, manganese etc.

Non-Ferrous Minerals- India’s reserves and production of non-ferrous minerals is not very satisfactory. However, these minerals, which include copper, bauxite, lead, zinc and gold play a vital role in a number of metallurgical engineering and electrical industries.

Ans)

Conventional energy	Non-Conventional energy
Coal, petroleum, natural gas and hydroelectric power are conventional sources of energy.	In this category, solar, geothermal, tidal, wind and biogas energy are included.
Except hydroelectric power, all these spread pollution.	These sources produce pollution free energy.
Except hydroelectric power all these sources are non-recyclable. They can not be replenished once they are used.	All these resources come under replenished sources. Their continuous uses are possible.
They are being used after non- conventional resources.	They are being used long ago.

Ans)

1. A number of minerals are found in beds or layers of sedimentary rocks.
2. They have been formed as a result of deposition, accumulation and concentration in horizontal strata.
3. Coal and some forms of iron ore have been concentrated as a result of long periods under great heat and pressure.
4. Another group of sedimentary minerals include gypsum, potash salt and sodium salt. These are formed as a result of evaporation especially in arid regions.

Ans) By the surfaced rocks-Another mode of mineral’s 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 by this process.

Base of hills-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.

Ans)

1. India is fortunate to have fairly rich and varied minerals. However, these are unevenly distributed.
2. In a broad sense, peninsular rocks contain most of the reserves of coal, metallic minerals, mica and many other non-metallic minerals.
3. Sedimentary rocks on the western and eastern flanks of the peninsula in Gujarat and Assam have most of the petroleum deposits. Rajasthan with the rock systems of the peninsula, has reserves of many non-ferrous minerals.
4. The vest alluvial plains of north India are almost devoid of economic minerals. These variations exist largely because of the difference in the geological structure, processes and time involved in the formation of minerals.
   • India is fairly rich in iron ore, manganese, bauxite, mica, lime stone.
   • Tin, lead, gold, copper and sulphur are deficient in India.

Ans) Copper is a metallic mineral. It has many uses. It is categorised as non- ferrous minerals. Being malleable, ductile and a good conductor, copper is mainly used in electrical cables, electronics and chemical industries. Besides, sculpture, utensils and decorating items are also made by this metal.

The Balaghat mines in Madhya Pradesh produce about 52 percent of the country’s copper. The Khetri mines in Rajasthan and Singhbhum district of Jharkhand are leading producers of copper.

Ans)

1. Toothpaste clears our teeth.
2. Some abrasive minerals like silica, limestone, aluminium oxide and various phosphate minerals do cleaning.
3. Fluoride which is used to reduce cavities, comes from a mineral fluorite.
4. Most toothpaste are made white with titanium oxide which comes from minerals called rutile, ilmenite and anatase. The sparkle in some toothpastes comes from mica.
5. The toothbrush and tube containing the paste are made of plastics from petroleum.

Ans)

1. Most of the minerals in India are nationalised and their extraction is possible only after obtaining due permission from the government.
2. But in most of the tribal areas of the north-east India, minerals are owned by individuals or communities.
3. In Meghalaya, there are large deposits of coal, iron ore, limestone and dolomite etc.
4. Coal mining in Jowai and Cherrapunjee is done by family member in the form of a long narrow tunnel, known as ‘Rat hole’ mining.
5. The National Green Tribunal has declared such activities illegal and recommended that these should be stopped forthwith.

Ans) A number of materials are extracted from the earth by digging its deep surface which are called minerals. Importance of minerals are the following: –

1. Minerals are basis of industrial development.
2. We obtain all means of transport, machines, equipments, farming tools, petroleum products, gold, silver and diamond jewelry, etc. from minerals.
3. Iron and coal are two such minerals without which industrial development is not possible.
4. Minerals have an important place in power resources. Without developing them no country or region can be developed industrially and economically. Hence, it is clear that minerals are very important for humans.
5. Everything used in our daily life is directly or indirectly related to minerals.

Ans) Mica is a kind of mineral which is a bad conductor of heat and electricity. Thus, it is used in electric materials. It is also used in colouring, preparing varnish etc. India is a leading producer of mica. About 60 per cent of world mica is traded by India. From the economic point of view four states of India have rich mica deposits that are Bihar, Jharkhand, Andhra Pradesh and Rajasthan.

Ans)

Ans) The impacts of mining are as follows: –

1. The dust and noxious fumes inhaled by miners make them vulnerable to pulmonary diseases.
2. The risk of collapsing mine roofs inundation and fires in coalmines are a constant threat to miners.
3. The water sources in the region get contaminated due to mining.
4. Dumping of waste and slurry leads to degradation of land, soil and increase in stream and river pollution.

Ans) Energy played a vital role in the industrialisation process of our nation and proved as boon for development of industries. Energy is required to run the large machines. Coal is a major source of energy and is essential for industrialisation in the country. Even it is significantly important in the development of steel and chemical industries. Petroleum also provides us energy. It provides fuel for road transport, aeroplanes and ships. Thus, energy is utmost important for developing industries in nation.

Ans)

1. Hydroelectric power is the cheapest source of energy.
2. Through hydroelectricity, irrigation facilities in India are collected by canals and pumping devices.
3. All other sources would be gradually finished but once a hydroelectric power house is formed, electricity can be produced forever because water is recyclable source of electricity.
4. Due to its cleanliness, hydroelectricity is also called aswhite coal. Being inexpensive, its importance is continuously increasing in industrial areas.

Ans) Nuclear or atomic energy is obtained by altering the structure of atoms. When such an alteration is made, much energy is released in the form of heat and this is used to generate electric power. Uranium and thorium, which are available in Jharkhand and the Aravalli ranges of Rajasthan are used for generating atomic or nuclear power. The monazite sands of Kerala is also rich in Thorium.

Ans) Conservation of the power resources- In the present economy, power resources are played the role of life force. As human body becomes dead without life force, just like, the various economic sectors-farming, industry, transport. trade, etc. can not be managed without power resources. Hence it is essential to conserve power resources available in the country, so that human needs related to power resources keep getting fulfilled always: Power resources should be used judiciously, power resources keep providing energy in future also and doesn’t pollute the environment as well.

Ans) Non-conventional energy resources- (1) Solar energy, (2) Wind energy, (3) Biogas, (4) Geothermal energy.

Solar energy has an important place in the non-conventional energy resources. Solar energy is particularly important for India because in India Sun shines for whole year and thus solar energy can be easily trapped. Most parts of our country usually have clear weather which provide best possibilities of trapping solar energy. India lacks power resources like hydroelectricity, coal and petroleum. There are possibilities of developing solar energy in the form of substitute for them.

Ans) Minerals generally occur in following forms: –

1. Indigneous and metamorphic rocks- See Answer of Textbook Exercises Q. 2 (iii).
2. In sedimentary rocks- See Ans. of Q. 2. (iii)
3. By the surface rocks- See Ans. of Q. 3.(1).
4. Base of hills- See Ans. of Q. 3.(2).
5. In ocean waters- The ocean waters contain vast quantities of minerals, but most of these are too widely diffused to be of economic significance. However, sommon salt, magnesium and bromine are largely derived from ocean waters. The ocean beds, too, are rich in manganese nodules.