Study Materials

NCERT Solutions for Class 7th Science

 

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Chapter 6. Physical and Chemical Changes

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Chapter Review:


  • When any object or material transforms its colour, size and taste etc that is known as changes. Ex :- curd from milk, chapatti from Flour, chair from wood. 

  • There are two kinds of changes. (i) Physical changes (ii) Chemical changes.

  • A change in which a substance undergoes a change in its physical properties is called a physical change.

  • A change in which one or more new substances are formed is called a chemical change.

  • This process of depositing a layer of zinc
    on iron is called galvanisation.

  • Large crystals of pure substances can be formed from their solutions. The process is called crystallisation.

  • Oxygen and water (or water vapour) is essential for rusting. 

 

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Chapter Contents: