7th Class Science Physical and Chemical Changes Question Bank Physical and Chemical Changes

  • question_answer
    DIRECTIONS: On the basis of following diagram/picture answer the questions given below: In an experiment a painted iron nail was placed into a beaker containing sea water (Fig 'A'). The beaker was left undisturbed for about 10 days. After 10 days, the nail began to rust (Fig 'B') which of the following statements is/are correct?               (i) Poor quality paint was used to paint iron nail. (ii) Oxygen and water cause rusting. (iii) Presence of salts in sea water enables rust formation faster.

    A)  (i) only                       

    B)  (ii) only

    C)  (iii) only        

    D)  (ii) and (iii)

    Correct Answer: D

    Solution :

     (ii) and (iii)


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