Chapter 4 of 5
Revision Notes
Combustion and Flame — Revision Notes
Gujarat Board · Class 8 · Science
Combustion and Flame revision notes for Gujarat Board Class 8 Science: 4 topics in quick points. Part of the Gujarat Board Class 8 Science syllabus.
45 questions5 concepts
Interactive on Super Tutor
Studying Combustion and Flame? Get the full interactive chapter.
Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for revision notes and more.
Free trial, no card needed.
Key Topics to Revise
1
What is Combustion?
- Combustion is a chemical process in which a substance reacts with oxygen to produce heat, and often light.
- The substance that undergoes combustion is called a combustible substance or fuel.
- Fuels can be solid (wood, coal, charcoal), liquid (kerosene, petrol, diesel), or gas (LPG, CNG, natural gas).
2
Ignition Temperature and Conditions for Combustion
- Every combustible substance has a specific ignition temperature – the minimum temperature needed for it to catch fire.
- A matchstick does not catch fire on its own because room temperature is below its ignition temperature.
- Rubbing a matchstick on the rough surface of a matchbox produces friction heat, raising the temperature above ignition temperature, causing it to burn.
3
How Do We Control Fire?
- Fire can be controlled by removing any one of the three requirements: fuel, oxygen, or heat.
- Water is the most common fire extinguisher – it cools the burning material below its ignition temperature AND water vapour cuts off oxygen supply.
- Water CANNOT be used for: (1) Electrical equipment fires (water conducts electricity – dangerous), (2) Oil/petrol fires (water is heavier than oil, sinks below, oil keeps burning on top).
4
Types of Combustion
- There are three main types of combustion: Rapid Combustion, Spontaneous Combustion, and Explosion.
- RAPID COMBUSTION: The substance burns rapidly, producing heat and light. Example: LPG burning in a gas stove, burning of a matchstick.
- SPONTANEOUS COMBUSTION: A material suddenly bursts into flames WITHOUT any apparent external cause (no matchstick or flame applied). Example: Phosphorus burns in air at room temperature.
Get complete notes with diagrams and examples
Full NotesKey Concepts
Combustion is a chemical processIgnition temperature is the lowest temperatureInflammable substances are materials that haveFor combustion to occurThere are three main types
Frequently Asked Questions
What are the important topics in Combustion and Flame for Gujarat Board Class 8 Science?
Key topics in Combustion and Flame include What is Combustion?, Ignition Temperature and Conditions for Combustion, How Do We Control Fire?, Types of Combustion. Study these first, then practise questions on each for Class 8 exams.
How should I revise Combustion and Flame for Class 8 exams?
Learn the core ideas first, then work through the 45 practice questions on Combustion and Flame. Revise definitions regularly and use flashcards for quick recall before the exam.
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
More resources for Combustion and Flame
For serious students
Get the full Combustion and Flame chapter — start free.
Quizzes, flashcards, an AI doubt solver and a study plan for Gujarat Board Class 8 Science. Free to start, no card needed.