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SAI INTERNATIONAL SCHOOL
CLASS-VII
SUBJECT- CHEMISTRY
TOPIC-PHYSICAL AND CHEMICAL CHANGES
SUB TOPIC- CONCEPT MAPPINP
LESSON NOTE
•1. Definition
A) Reversible Change
•2. Properties and examples
B) Irreversible Changes •1. Definition
2.Properties and examples
C) Physical Changes •1. Definition
Properties
Different types
D) Chemical Changes •1. Definition
Properties
Rusting
Browning of fruits
E) Different types of chemical Reaction of vinegar and baking soda
reaction Displacement Reaction
Combination Reaction
Dissociation Reaction
Definition
F) Crystallisation
Method
G)Formation of salt
CHANGE:
A change refers to a noticeable difference in the shapes, size, colour, state, internal
structure or any other properties.
REVERSIBLE CHANGES:
A change in which the original substance can be reversed back to its own form. The
change is temporary.
Examples of reversible changes are melting of ice, making toys using clay- etc
IRREVERSIBLE CHANGES:
A change in which the original substance cannot be recovered. It is a permanent
change
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