NCERT Class VII Science Solutions: Chapter 6-Physical and Chemical Changes Part 1 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 1:

Classify the changes involved in the following processes as physical or chemical changes:

  1. Photosynthesis
  2. Dissolving sugar in water
  3. Burning of coal
  4. Melting of wax
  5. Beating Aluminum to make Aluminum foil
  6. Digestion of food

Answer:

Physical Changes:

B. Dissolving sugar in water

D. Melting of wax,

E. Beating Aluminum to make Aluminum foil.

As Showing in Images is a Dissolving Sugar in Water, Melting …

Chemical Changes:

A. Photosynthesis,

C. Burning of coal,

F. Digestion of food,

As Showing in Images is a Photosynthesis, Burning of Coal, D …

Question 2:

State whether the following statements are true or false. In case a statement is false, write the corrected statement in your notebook.

  1. Cutting a log of wood into pieces is a chemical change. (True/False)
  2. Formation of manure from leaves is a physical change. (True/False)
  3. Iron pipes coated with zinc do not get rusted easily. (True/False)
  4. Iron and rust are the same substances. (True/False)
  5. Condensation of steam is not a chemical change. (True/False)

Answer:

  1. Cutting a log of wood into pieces is a chemical change. (False)
  2. Formation of manure from leaves is a physical change. (False)
  3. Iron pipes coated with zinc do not get rusted easily. (True)
  4. Iron and rust are the same substances. (False)
  5. Condensation of steam is not a chemical change. (True)