NCERT 8th Class (CBSE) Social Science: Minerals and Power Resources

Question: Distinguish between the following:

Answer: 1. Metallic and non-metallic minerals:

Metallic minerals:

1. Metallic minerals are metals such as iron, gold and copper.
2. They are pound in igneous and metamorphic rocks.

Non-Metallic minerals:

1.  Non-metallic minerals don not have metals such as Nitrate, Sulfur, Potash, Salt and coal.
2. They are found in sedimentary rocks.
3. They are dull and soft.

2. Conventional and Non-Conventional power resources:

Conventional:

1. The resources of energy which have been in use for a long time. Eg: Coal, Petroleum, natural gas, water power.
2. They have limited reserves and are exhaust-able except water.
3. They cause pollution when used as they emit smoke and ash.
4. They are very expensive to be maintained, stored and transmitted as they are carried over long distance through transmitted grid and lines.

Non-Conventional:

1. The resources which are yet in the pro-cell of development over the past few years are recenter developed it includes solar, wind, tidal, bio-gas and bio-mass, geothermal.
2. They have unlimited reserve. They are inexhaustible.
3. They are generally pollution free.
4. They are less expensive due to local use and easy to maintain.

Question: What are the main characteristics of mineral?

Answer: Following are the main characteristics of minerals:

1. They are unevenly distributed over the earth’s surface.
2. They are mixed up with large variety of impurities.
3. The mineral resources are exhaust.