The document defines combustion as a chemical process where a substance reacts with oxygen in air to produce heat and light. There are several types of combustion described, including spontaneous, rapid, complete, and incomplete combustion as well as explosions. Rapid combustion occurs when a substance burns quickly, producing heat and flame, often with the introduction of external heat. Incomplete combustion results in only partial burning of a fuel due to a lack of oxygen or low temperature, producing carbon monoxide. For combustion to occur, there must be a combustible substance, a supply of oxygen (air), and enough heat to raise the substance to its ignition temperature.

2. A CHEMICAL PROCESS IN
WHICH A SUBSTANCE
REACTS WITH THE OXYGEN
OF AIR TO GIVE HEAT &
LIGHT IS CALLED
COMBUSTION.

3. • SPOTANOEUS COMBUSTION
• RAPID COMBUSTION
• COMPLETE COMBUSTION
• INCOMPLETE COMBUSTION
• EXPLOTION

4. RAPID COMBUSTION
•Combustion in which a substance burns
rapidly and produces heat and flame is
known as rapid combustion, such as
combustion of natural gas, LPG, petrol etc.
• This is usually attained by introducing
external heat.
• Substances which undergo rapid
combustion have lower ignition temperature

5. • When a substance suddenly starts
burning into a flame; without the
supply of any external cause such as
heating; the combustion is called
spontaneous combustion.
• Substances; which have relatively
low temperature of ignition
generally burn by spontaneous
combustion.

6. • A reaction or process which
entails only partial burning of a
fuel.
• This may be due to a lack of
oxygen or low temperature,
preventing the complete chemical
reaction.

8. • A reaction or process which
entails only partial burning of
a fuel.
• This may be due to a lack of
oxygen or low temperature,
preventing the complete
chemical reaction.
• Carbon monoxide is
produced as a by product from
incomplete combustion

10. • When combustion is
accompanied by sudden
production of heat, sound
and large amount of gas, it is
called explosion.
• Firecrackers and bombs are
substances which show
explosion

11. • Phosphorous and sulphur start burning
instantaneously; at room temperature.
• Haystacks, linseed oil, coal, pyrite, etc.
sometimes start burning suddenly with
flame because of increase in
temperature.
• In coal mines, fire breaks out many a
times because of combustion of coal
dust.
• Fire often breaks out suddenly
because of increase in temperature due
to sun or friction.

13. •COMBUSTIBLE
•NON COMBUSTIBLE SUBSTANCES

14. • SUBSTANCES WHICH CAN BURN ARE
CALLED AS COMBUSTIBLE
SUBSTANCES.

15. COAL
WOOD LOG

16. WATER
BRICK

17. • SUBSTANCES WHICH DO NOT
BURN ARE CALLED NONCOMBUSTIBLE
SUBSTANCES.

18. CONDITIONS
NECESSARY FOR COMBUSTION

19. CONDITIONS
NECESSARY FOR COMBUSTION
• PRESENCE OF THE COMBUSTIBLE SUBSTANCES
( A SUBSTANCE WHICH CAN BURN)
• PRESENCE OF A SUPPORTER OF OXYGEN ( I.E.
AIR)
• HEATING THE COMBUSTIBLE SUBSTANCES TO
ITS IGNITION TEMPERATURE.