minerals and power resources 8th standard geography notes
Answers
Answer:
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 nation.
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 Deccan 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.
Aluminum is used in automobile, airplanes, bottling industry, building and in kitchen cookware.
Mica is used to make electrical appliances and glassmaking 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.
Answer:
Question 1.
Answer the following questions.
(i) Name any three common minerals used by you every day.
(ii) What is an ore? Where are the ores of metallic minerals generally located?
(iii) Name two regions rich in natural gas resources.
(iv) Which sources of energy would you suggest for
(a) rural areas (b) coastal areas (c) arid regions
(v) Give five ways in which you can save energy at home.
Answer:
(i) Three common minerals used by us in day-to-day life are copper, iron and salt.
(ii) Ore is the raw me tat-found in the earth mixed with other materials or impurities.
They are generally located in igneous or metamorphic rocks.
(iii) Two regions in India rich in natural gas resources are Jaisalmer and Krishna-Godavari delta.
(iv) (a) For rural areas, solar energy and wind energy are feasible options. There aren’t many high-rise buildings to act as an obstacle for sunlight or to break the momentum of wind. ”
(b) For coastal areas, wind energy and tidal energy are good choices.
(c) For arid regions, wind energy and solar energy are feasible, for reasons similar to rural areas.
(v) Five ways in which one can save energy at home:
Promoting the use of solar energy as much as possible.
Using biogas as cooking fuel.
Drying clothes in sunlight instead of electric dryers to prevent emissions and unnecessary use of electricity.
Avoiding misuse of electricity; switching off fans and lights when not required.
Using pressure cookers for cooking.
Question 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.
(ii) Which one of the following is not a producer of mica?
(a) Jharkhand
(b) Karnataka
(c) Rajasthan
(d) Andhra Pradesh
(iii) Which one of the following is a leading producer of copper in the world?
(a) Bolivia
(b) Ghana
(c) Chile
(d) Zimbabwe
(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.
Answer:
(i) (c), (ii) (b), (iii) (c), (iv) (d).
Question 3.
Give reasons.
(i) Environmental aspects must be carefully looked into before building huge dams.
(ii) Most industries are concentrated around coal mines.
(iii) Petroleum is referred to as “black gold”.
(iv) Quarrying can become a major environmental concern.
Answer:
(i)
Because of the following reasons:
Dams create an imbalance in the earth’s equilibrium.
Deforestation leads to environmental pollution.
People are displaced.
Cities/villages/towns are shifted causing untold hardships to people.
Flood threats loom large.
Earthquake threats.
Silting of lakes a problem.
(ii) Presence of coal mines around industries reduces the costs of transportation and also ensures easy availability of fuel.
(iii) Petroleum is a very valuable fossil fuel. It is used for running all types of machinery, transport vehicles, from a bicycle to an aeroplane.
(iv) After quarrying, pits are not covered so they may cause environmental hazards.
Question 4.
Distinguish between the following.
(i) Conventional and non-conventional sources of energy.
(ii) Biogas and natural gas.
(iii) Ferrous and non-ferrous minerals
(iv) Metallic and non-metallic minerals.
Answer:
(i)