3.3  Additional Questions :

1.  What is a mineral.
Ans: Minerals are found in the earth and are naturally occurring substances. They are not made by man. They are found in rocks and water. They are chemical substances made of elements.

2.  How are minerals extracted from earth.
Minerals are extracted by mining, drilling and quarrying.

3.  What are the classification of the minerals.
They are classified into metallic minerals and Non-metallic minerals.Metallic mineral are further divided into ferrous and non-ferrous minerals.

4.  What do the three R’s stand for.
It stands for Reduce, Reuse and Recycle.
Reduce – to use lesser quantity.
Re-use – to put it again into use without changes.
Recycle – to put it again into use with changes.

5.  What is bio-gas.
It is gaseous fuel obtained from the  decomposition of organic wastes like dead plants and animal material or animal dung.

6.  Mention few minerals and their uses.
i) Gold, Silver and Platinum are used in jewellery.
ii) Copper is used in the coin industry and for making pipes and wires.
iii) Silicon obtained from quartz is used in the  computer industry.
iv) Aluminium obtained from bauxite ore is used in automobiles and airplanes, buildings and even in kitchen cookware.

7.  What is a) Extraction b) Mining c) Shaft mining    d) Quarrying  .

a) Extraction is the process of taking out minerals from under the earth’s surface so that useful materials can be derived from them.
b) Mining is a process of extraction ( taking out) of minerals from rocks under the earth’s surface.
c) Shaft mining is a method of extraction in which deep bores (called shaft) are made to reach the mineral deposits lying deep under the earth.
d) Quarrying is the process of extraction in which minerals lying very close to the surface are extracted just by digging them out.

8.  What are fossil fuels.
Fossil fuels are what the remains of plants and animals got  converted into after they remained buried under the earth million years ago.