• Third Preparatory, Science, Term 1 (English edition).
• This unit has three lessons (1) Types of Chemical Reactions, (2) Combustion Reactions and Environmental Pollution, (3) Smoking and Its Hazards.
• In the first lesson you learn to sort reactions into families and to predict what happens when a metal meets oxygen, water, an acid or a salt solution.
• In the second lesson you study one very important family, combustion, and see how it affects the air we breathe.
• In the third lesson you apply the same chemistry to a human habit that harms both people and the environment.

🌳 Concept tree

1. Unit 1 — Chemical Reactions and Their Environmental Impacts
2. Types of Chemical Reactions
3. │ ├── 1.1 Starting point: what is a chemical reaction?

│ ├── 1.2 Direct combination reactions

│ ├── 1.3 Decomposition reactions

│ ├── 1.4 Single replacement reactions

│ ├── 1.5 Double replacement reactions

│ ├── 1.6 Oxidation–reduction (redox) reactions

│ └── 1.7 Summary of Lesson 1

• ├── Lesson 2 Combustion Reactions and Environmental Pollution
• │ ├── 2.1 Why do some things burn easily?

│ ├── 2.2 The combustion triangle

│ ├── 2.3 Ignition point and flammability

│ ├── 2.4 Life application: how a match lights

│ ├── 2.5 Combustion of metals and non-metals

│ ├── 2.6 Complete and incomplete combustion

│ ├── 2.7 Detecting the products of combustion

│ ├── 2.8 Properties of the combustion products

• │ ├── 2.9 Environmental pollution from combustion

│ └── 2.10 Summary of Lesson 2

├── 3.1 A behaviour that threatens public health

• ├── 3.2 The tobacco plant and the products of tobacco combustion

├── 3.3 What tobacco contains

├── 3.4 Harmful effects on health

├── 3.5 Environmental damage caused by smoking

├── 3.6 Types of smoking and ways of exposure

├── 3.7 Preventing smoking: how to say no

└── 3.8 Summary of Lesson 3