NCERT Solutions for Class 8 Science Chapter 5: Coal and Petroleum

The chapter begins by telling us about the different resources available in nature. We read about fossil fuels. We get to know about coal, its characteristics and how it is formed. We also read about the different substances that are formed from coal. The chapter then goes on to tell us about petroleum and its formation. It also lists out the various constituents of petroleum and their usage. The chapter ends by telling us about natural gas, its usage and advantages, and its resources.

• Natural resources on earth can be classified into two categories: inexhaustible natural resources and exhaustible natural resources.
• This chapter focuses on exhaustible natural resources like coal, petroleum and natural gas.
• We learn about the process of formation of coal which is more than 300 million years old.
• Under high pressure for 300 million years, dead plants got converted into coal.
• The chapter also tells us about the different forms of coal.
• We also learn about the formation of petroleum.
• The dead remains of living organisms in the sea, under high pressure for millions of years, lead to petroleum formation.
• The chapter goes on to explain the process of refining of petroleum.
• The chapter also lists the various uses of petroleum in different fields.
• The most popular form of natural gas is known as CNG (Compressed Natural Gas).
• It is also used in the manufacturing of various products.
• The chapter concludes by warning us about the depletion of these resources.
• We also learn about the harmful side-effects of using these exhaustible resources on the planet.