This chapter, 'Combustion And Flames', examines how the related terms combustion and flames can be distinguished, which might expand our perception of basic chemistry. The lesson attempts to describe and understand the nature of the substances as some substances combust rather than go through burning, while some generate flames on burning. Students also discover numerous ways of preventive measures to be taken to extinguish the fire.
The chapter strategy begins with the concept of ignition temperature and the factors responsible for combustion to take place which, divides the combustion into three types including:
1. Rapid combustion
2. Spontaneous combustion
The chapter represents fuel efficiency with decreasing order of calorific values of different fuels. The chapter further presents a broad idea regarding the measures to control fire using distinct components of fire extinguishers in diverse situations. Students also learn the relationship between poisonous gases produced by the incomplete combustion of fuels and their effect on human health.
Additionally, this chapter highlights the three-zone of the flame identified by their precise colour. The chapter's attraction centres are the various experimental views that expand the knowledge on the practical concept. It further explains the ideal characteristics of good fuel with slight mention of combustible substances. Students also learn to apply the experimental approach. Finally, the chapter helps them to work out the conclusions by showing them the necessary condition for complete combustion.
The chapter provides essential information on the negative impact of burning fuels and their effect on human health. Students also learn the reason behind acid rain and the gases involved in them. The chapter further elaborates on detrimental impacts on the environment and the aquatic ecosystem due to acid rain. Finally, the chapter concludes by telling the students about the precautionary measures that can be taken to prevent this harmful effect.