NCERT solutions for Science Exemplar Class 8 chapter 5 - Coal and Petroleum [Latest edition]

Various materials which are obtained from nature are called natural resources. Which of the following is not a natural resource?

Air is a natural resource and cannot be exhausted by human activities. It is known as inexhaustible natural resource. Which of the following is another inexhaustible natural resource?

Which of the following is a pair of exhaustible natural resources?

Coal is processed in industries to get some useful products. Which of the following is not obtained from coal?

Exhaustible natural resources are

Fossil fuels are obtained from

Coal is formed from the remains of

Which substance is formed by the carbonisation of dead vegetation?

Naphthalene balls are obtained from coal tar and are used as

Which of the following is not a constituent of petroleum?

Petroleum was formed from organisms

Choose the correct statement from the following.

You are provided with a mixture of petroleum and water. Can you suggest a method to separate the two?

What does CNG stand for and why is it considered to be a better fuel than petrol?

Name the petroleum product used as fuel for stoves, lamps and jet aircrafts.

Fill in the blanks in the following sentence.

Coal is one of the ______ used to cook food.

Fill in the blanks in the following sentence.

When heated in air, coal burns and produces mainly ______ gas.

Fill in the blanks in the following sentence.

Coal tar is a black, thick ______ with an ______ smell.

Fill in the blanks in the following sentence.

Petroleum, ______ and ______ are fossil fuels. 

Fill in the blanks in the following sentence.

Forests and coal are ______ natural resources.

The underlined word in the following sentence have been jumbled up. Write them in their correct form.

Loca is obtained from mines.

The underlined word in the following sentence have been jumbled up. Write them in their correct form.

Umpetlore is a fossil fuel.

The underlined word in the following sentence have been jumbled up. Write them in their correct form.

Rineryfe is a place where various fractions of petroleum are separated.

The underlined word in the following sentence have been jumbled up. Write them in their correct form.

Keenrose is a fuel used in jet crafts. 

The underlined word in the following sentence have been jumbled up. Write them in their correct form.

Nutsgilh is an example of inexhaustible natural resources.

The slow process of conversion of dead vegetation into coal is called ______.

Coal and petroleum are formed from the dead remains of organisms and are known as ______.

The black thick liquid with ______ smell is known as coal tar.

During the processing of coal to get coke, coal tar and ______ are also obtained.

The process of separating the various constituents of petroleum is known as ______.

Excessive burning of fossil fuels is a major cause of ______.

Write True/False against the following statement.

Oxygen in air is an exhaustible natural resource.

Write True/False against the following statement.

Resources which are present in unlimited quantity in nature are called exhaustible natural resources.

Write True/False against the following statement.

Wildlife is an exhaustible natural resource.

Write True/False against the following statement.

Under high temperature and pressure, dead plants get slowly converted to coal. 

Write True/False against the following statement.

CNG is less polluting fuel than petrol and diesel.

Sunlight and air are inexhaustible natural resources. Comment.

Some natural resources are given below. Classify them into the exhaustible and inexhaustible natural resources.

Write two important uses of coke.

Write the characteristics and some important uses of coal.

Look at figure where petroleum and natural gas deposits are shown. Why do we find oil layer above water layer?

Fill in the blanks and complete the story.

About 300 million years ago, the earth had dense ______ in low lying wetland areas. Due to natural processes like ______ these forests got buried under the ______ As more ______ deposited over them, they were compressed. The ______ also rose as they sank deeper and deeper. Under high ______ and high ______ , dead plants got slowly converted into coal.

Match the items given in Column I with the items of Column II.

Name the products obtained and their uses when coal is processed in industry.

We say fossil fuels will last only for a few hundred years. Comment.

We read in newspapers that burning of fuels is a major cause of global warming. Explain why.

While driving what are the tips we must follow to save petrol/diesel/natural gas?

Imagine that all the exhaustible natural resources are exhausted by human activities. Do you think survival of living beings would be possible? If yes, why? If not, why not?

Why petrol is exhaustible natural resource whereas sunlight is not? Explain.

Write some important uses of the various constituents of petroleum.

Coal reserves are said to be enough to last for another hundred years. Do you think we need to worry in such case? Why or why not?

What steps would you suggest for the judicious use of fuels? 

Complete the crossword in figure with the help of the clues :

Across

1. Fuels obtained from dead remains of living organisms. (6, 5)

2. A process by which the various constituents of petroleum are separated. (8)

3. A porous black substance obtained from coal. (4)

4. Another name for motor fuel. (6)

Down

5. The substance obtained by carbonisation. (4)

6. Fuel for heavy motor vehicles. (6)

7. A petroleum product used for road surfacing. (7)

8. Dead remains of sea animals got converted into it. (9)