Classify various materials we use in our lives.
All the materials we use can be broadly classified into two groups :
(a) Natural Resources, (b) Man-made Resources.
(a) Natural resources are those resources which are present in our nature, gifted by God. They can be freely used. Soil, air, sunlight, water, wildlife, etc. are some natural resources.
(b) Man-made resources are those resources which are formed by various efforts of man and are artificial. Plastics, fibres, electricity, etc. are all artificial resources.
On availability of materials natural materials can further be classified as :
(i) Inexhaustible Natural Resources : Those resources which are present in unlimited quantity and will never get exhausted by human activities. Sunlight, air, soil, etc. are some inexhaustible natural resources.
(ii) Exhaustible Natural Resources :
Those resources which are available in limited amount and will get finished by human activities. Petroleum, coal, wildlife, forests, etc. are some examples of exhaustible natural resources.
Fossil fuels are ________, ________ and ________.
Name the petroleum product used for surfacing of roads.
Bitumen or coaltar is used for surfacing of roads.
Process of separation of different constituents from petroleum is called __________.
Describe how coal is formed from dead vegetation. What is this process called?
Millions of years ago, dense forest and animal got buried under the soil due to natural process like floods, earthquakes and thunder storms. When they got buried deep in the soil, they were exposed to very high pressure and temperature. Under these conditions, these slowly got converted into coal. This process of formation of coal vegetation is called carbonization.
What are the advantages of using CNG and LPG as fuels?
Advantages of CNG—Compressfed Natural Gas and LPG—Liquefied Petroleum Gas are:
i) Both fuels burn with clean flame that does not produce smoke.
ii) They give more heat and energy as compared to other fuels.