Solutions of Combustion, Fuels And Flame from SCIENCE For Class 8

This topic provides knowledge about combustion, which is a chemical process of burning a substance (fuel) in the presence of air (oxygen). A new product is formed on the burning of fuel, and the sound of crackling or explosion is produced.

This topic focuses on combustible and non-combustible substances. It explains four types of combustion such as explosive combustion, spontaneous combustion, rapid combustion, and slow combustion.

The topic discusses the conditions required for the process of combustion. The three preconditions for combustion are combustible material, air (oxygen), and ignition temperature. It also discusses steps to extinguish fire and precautions.

The topic explains that fuel is a material to create fire and burning produces light and fire. It describes the kinds of fuels with examples. It also discusses the characteristics of fuels.

This topic deals with the definition of the calorific value of fuel. It tells that a fuel is better if its calorific value is high. The calorific value of a few common solid, liquid and gaseous fuels is given. Hydrogen has the highest calorific value.

Through this topic, we will learn about the natural resources of fuel such as wood, charcoal, fossil, coal, petroleum, natural gas, etc. We will also study the characteristics of good fuel.

This topic elucidates the flame and also describes the different coloured zones in the flame. There are four zones in a flame: blue zone, dark inner zone, luminous zone, and outermost non-luminous zone.

The topic describes the wicks, their characteristics, and how wicks are placed differently for different fuels. It also discusses the chemical history of a candle and the differences between burning and breathing.