Types of changes - Class 6
i)
|
Natural Change
|
Man-Made Change
|
|
The
changes which are brought about by the nature.
Examples:
·
Growth
in plants, animals and human beings.
·
Change
in seasons.
·
Occurrence
of lightning.
·
Change
of weather.
|
The
changes which are brought about by man.
Examples:
·
Burning
of Fuels.
·
Chemical
reactions.
·
Making
of glass
·
Making
of furniture.
|
ii)
|
Temporary(reversible) Change
|
Permanent(irreversible) Change
|
|
The
changes which can be reversed by change in conditions.
Examples:
·
Change
in the state of a substance.
·
Freezing
of water.
|
The
changes which cannot be reversed by change in conditions.
Examples:
·
Conversion
of seed to plant.
·
Burning
of Magnesium.
|
iii)
|
Slow Change
|
Fast Change
|
|
The
changes which occur very slowly over days, months or years.
Examples:
·
Growth
of a tree from a seed.
·
Change
of Seasons.
|
The
changes which occur very rapidly in seconds or minutes.
Examples:
·
Occurrence
of lightning.
·
Burning
of fire crackers.
|
iv)
|
Periodic Change
|
Non-Periodic Change
|
|
The
changes which occur periodically at regular intervals.
Examples:
·
Change
of Seasons.
·
Motion
of swing.
·
Movement
of a pendulum.
|
The
changes which do occur periodically at regular intervals.
Examples:
·
Change
of weather.
·
Eruption
of volcano.
·
Rusting
of Iron.
|
v)
|
Desirable Change
|
Undesirable Change
|
|
The
changes which produce useful results.
Examples:
·
Change
of milk to curd.
·
Making
of glass.
·
Burning
of wood in a furnace.
|
The
changes which produce useless or harmful results.
Examples:
·
Milk
turning sour.
·
Breaking
of glass.
·
Burning
of wood in a forest fire.
|
vi)
|
Physical Change
|
Chemical Change
|
|
1.
No
new substance is formed.
2.
Composition
of original substance is not altered.
3.
Properties
of the original substance are not altered.
·
Melting
of Ice.
·
Addition
of sugar to Water.
·
Heating
of Platinum wire.
·
Magnetizing
of Iron.
|
1.
New
substance is formed.
2.
Composition
of original substance is altered.
3.
Properties
of the original substance are altered.
·
Burning
of Magnesium
·
Rusting
of Iron.
·
Change
of milk to Curd
·
Burning
of Sulphur.
|
vii)
|
Exothermic Change
|
Endothermic Change
|
|
A chemical
reaction which proceeds with evolution of heat energy is called an exothermic
change.
Examples:
·
Burning
of coal or Fuels
·
Glowing
of an electric lamp.
|
A chemical
reaction which proceeds with absorption of heat energy is called an
endothermic change.
Examples:
·
Melting
of Ice
·
Dissolving
Ammonium chloride in Water.
|
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