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NCERT Solutions for Class 8th Science

 

Page 5 of 5

Chapter 5. Coal And Petroleum

Additional Questions With Solutions

 

 

 

Additional Questions With Solutions


Q12: Name the petroleum product is used for surfacing of roads?

Ans: These days bitumen, a petroleum product is used for surfacing the roads in place of coaltar.

Q13: Described how coal is formed from dead vegetation. What is this  called?

Ans: About 300 million years ago, earth was having dense forests in low lying wet land areas. Due to earthquakes and vocaline eruptions, these forest got buried under the soil. As more soil deposited over them, they were compressed. The temperature also raised as they sank deeper and deeper. Due to high temperature and lack of oxygen dead plants inside the earth got slowly converted to coal.

Q14: Explain why fossil fuels are exhaustible natural resources?

Ans: Fossile fuels are present in nature in limited quantity and are being exhausted abundantly by us that is why fossil fuels are called exhaustible natural resources.

Q15: Describe characteristics and uses of coke.

Ans: coke is a tough porous black substance It is almost pure form of carbon. It is used in manufacture of steel and in the extraction of many metals.

Q16: Explain the formation of petroleum?

Ans: Petroleum is formed from organism living in the sea. When these organisms died, their bodies settle at the bottom of sea and got covered with layers of sand and clay. Over million of years, they were transformed into petroleum, oil and natural gas under the absence of air and presence of high pressure.

 

Page 5 of 5

 

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