Combustion and Flame — Class 8 Science NCERT Solutions (Free)

Free step-by-step NCERT solutions for Class 8 Science chapter "Combustion and Flame" — 8 important questions with detailed answers for CBSE board exam preparation.

TL;DR: Free step-by-step NCERT solutions for Class 8 Science chapter "Combustion and Flame" — 8 important questions with detailed answers for CBSE board exam…

By Syllab.in · Updated Jun 14, 2026

Key Questions Covered:

What is combustion?
Define the term 'ignition temperature'.
What is spontaneous combustion? Give one example.
Describe the three zones of a flame with a diagram explanation.
What is the difference between burning and combustion?
How can we control/extinguish a fire? Name two methods.
+ 2 more questions in the full chapter

Solutions Summary:

Question	Status
What is combustion?	✓ Solved
Define the term 'ignition temperature'.	✓ Solved
What is spontaneous combustion? Give one example.	✓ Solved
Describe the three zones of a flame with a diagram explan…	✓ Solved
What is the difference between burning and combustion?	✓ Solved
How can we control/extinguish a fire? Name two methods.	✓ Solved

Showing 6 of 8 questions

Q1: What is combustion?

Combustion is a rapid chemical reaction between a substance and oxygen, releasing heat and light energy. It requires three conditions: fuel, oxygen (supporter of combustion), and ignition temperature (heat source).

Q2: Define the term 'ignition temperature'.

Ignition temperature is the minimum temperature to which a substance must be heated to start burning. Different substances have different ignition temperatures. Example: paper ignites at 451°C, wood at 300°C, phosphorus at 34°C.

Q3: What is spontaneous combustion? Give one example.

Spontaneous combustion is burning of a substance without external heat application, occurring when ignition temperature is reached by internal heat generation. Example: white phosphorus ignites spontaneously in air at room temperature (34°C).

Q4: Describe the three zones of a flame with a diagram explanation.

Three flame zones: 1) Outermost zone (blue, hottest, complete combustion), 2) Middle zone (yellow, incomplete combustion, sooty), 3) Innermost zone (dark/black, unburnt fuel and wax vapor). Innermost is coolest, moves away from flame.

Q5: What is the difference between burning and combustion?

Burning is a slow oxidation process releasing heat without flames/light (example: rusting of iron, browning of fruits). Combustion is rapid oxidation with visible flames and bright light release. Combustion is a type of burning but at much faster rate.

Q6: How can we control/extinguish a fire? Name two methods.

Fire control methods: 1) Remove fuel source (not using combustible near fire), 2) Cut oxygen supply (covering fire with blanket/sand/CO2), 3) Lower temperature (throwing water to cool the fuel below ignition point). All work by removing one of three combustion conditions.

Showing 6 of 8 questions. Visit the full page for complete solutions.