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SAI International School
Subject - Chemistry
Class - VIII
Topic – COMBUSTION AND FLAME

Sub-Topic-Introduction, Combustion, Combustible and Non-
Combustible Substance

LESSON NOTES

INTRODUCTION

We have already discussed fuels in the previous chapter. We know that some substances burn
whereas others do not.

We also know that the burning of substances is a chemical change.

Moreover, the way of burning also varies from substance to substance. Let us discuss more in
detail.

What is combustion?
It is a chemical process in which a substance reacts with oxygen (in the air) to give heat and light
is called combustion.

The light can be in the form of a flame or the form of a glow. For example, when wood burns, it
burns with a flame whereas when charcoal burns, it produces light in the form of glow.

Let us recap some of the combustion processes which we have discussed earlier.

1. Combustion of Magnesium
When a magnesium ribbon is heated, it starts burning or undergoes combustion. It combines
with oxygen to form magnesium oxide and gives heat and light. It burns with a dazzling white
flame.
Magnesium + Oxygen Magnesium oxide + Heat + Light
_________ + ______ ________
*The chemical equation is to be written by the children.

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