PPT: Combustion and Flame | Science Class 8 PDF Download

 Page 1


COMBUSTION
& FLAME
Page 2


COMBUSTION
& FLAME
C O N T E N T S
What is Combustion?
1
Types of Combustion
2
What is a Fuel?
4
Flame
3
Fuel Efficiency
5
Page 3


COMBUSTION
& FLAME
C O N T E N T S
What is Combustion?
1
Types of Combustion
2
What is a Fuel?
4
Flame
3
Fuel Efficiency
5
WHAT IS COMBUSTION
The process in which a substance undergoes a
chemical reaction in the presence of air (oxygen) to
produce heat and light is called combustion.
Examples: 
Burning of Wood or Coal to heat your home.
Burning of Petrol or Diesel to run your Car.
Combustion of Natural Gas or LPG to cook for on your
stovetop
For the production of energy in thermal power plants
Fireworks
Page 4


COMBUSTION
& FLAME
C O N T E N T S
What is Combustion?
1
Types of Combustion
2
What is a Fuel?
4
Flame
3
Fuel Efficiency
5
WHAT IS COMBUSTION
The process in which a substance undergoes a
chemical reaction in the presence of air (oxygen) to
produce heat and light is called combustion.
Examples: 
Burning of Wood or Coal to heat your home.
Burning of Petrol or Diesel to run your Car.
Combustion of Natural Gas or LPG to cook for on your
stovetop
For the production of energy in thermal power plants
Fireworks
COMBUSTIBLE SUBSTANCES
Substances that go under combustion are known as
combustible substances. Combustible substances are also
known as fuel. 
The fuel may be in a solid, liquid or gas state. 
Wood, Charcoal, LPG, Kerosene, Petrol, Diesel, etc. 
Page 5


COMBUSTION
& FLAME
C O N T E N T S
What is Combustion?
1
Types of Combustion
2
What is a Fuel?
4
Flame
3
Fuel Efficiency
5
WHAT IS COMBUSTION
The process in which a substance undergoes a
chemical reaction in the presence of air (oxygen) to
produce heat and light is called combustion.
Examples: 
Burning of Wood or Coal to heat your home.
Burning of Petrol or Diesel to run your Car.
Combustion of Natural Gas or LPG to cook for on your
stovetop
For the production of energy in thermal power plants
Fireworks
COMBUSTIBLE SUBSTANCES
Substances that go under combustion are known as
combustible substances. Combustible substances are also
known as fuel. 
The fuel may be in a solid, liquid or gas state. 
Wood, Charcoal, LPG, Kerosene, Petrol, Diesel, etc. 
TYPES OF COMBUSTION
Rapid Combustion
Rapid energy needs
external heat energy for
the reaction to occur. 
Combustion produces a
large amount of heat and
light energy and does so
rapidly. 
The combustion will carry
on as long as the fuel is
available.
Spontaneous
it requires no external energy
for the combustion to start. 
It happens due to self-
heating. 
A substance with low-
ignition temperatures gets
heated, and this heat is
unable to escape.
In the presence of sufficient
oxygen, the temperature
rises above the ignition point
and combustion
Explosion
Explosive Combustion
happens when the
reaction occurs very
rapidly. 
A large amount of gas
formed in the reaction is
liberated. Such a reaction
is called an explosion.  
The reaction occurs when
something ignites to
produce heat, light and
sound energy.