Revision Notes for CBSE Class 8 Social Science Chapter 25 – Free PDF Download
Free PDF download of Revision Notes Social Science Class 8 Solutions Chapter 25 – Mineral and Power Resources solved by Expert Social Science Teachers on CoolGyan.Org. All Chapter 25 – Mineral and Power Resources Notes for NCERT to help you to revise complete Syllabus and Score More marks.
Social Science NCERT Solutions for Class 8
|Chapter Name||Mineral and Power Resources|
|Subject||Geography Revision Notes|
Quick Revision 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.