Page 29 - ICSE Chemistry 8

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2 Physical and Chemical Changes

Learning Outcomes Key Concepts
Students will be able to
• Changes—A Review
• illustrate diff erent changes occurring in nature with example learned in
previous classes. • Classifi cation of Changes
• perform some ac vi es to show some well-known changes. • Reversible and
Irreversible Changes
• diff eren ate between physical and chemical changes and classify the
changes. • Periodic and Non-
Periodic Changes
• Desirable and
Undesirable Changes
• Slow and Fast Changes
• Natural and Man-made
Changes
• Physical and Chemical
Changes
• Changes Involving
Energy Changes

Warm Up Activity
Based on your previous knowledge about physical and chemical changes, classify the following changes under
the given categories.
Diges on of food, folding of paper, dissolving salt in water, clo ng of blood, cu ng of a cloth, bending of a glass
tube by hea ng, magne sa on of an iron bar by means of electricity, crystallisa on of sugar from its solu on,
mel ng of bu er, ripening of fruits, curdling of milk, freezing of water, sublima on of camphor, rus ng of iron,
burning of fuel, boiling of water, cooking of food, blowing air into a balloon, mel ng of wax, fermenta on
Physical Changes
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Chemical Changes
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CHANGES—A REVIEW

In our everyday lives, a lot of changes occur around us. Various substances undergo one type of change or
the other. A change refers to the transforma on of a substance from one form to another. For example, an

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