Page 1 - 4.HOME ASSIGNMENT-(THOMSON'SMODEL OF AN ATOM AND ITS DRAWBACKS)
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SAI International School
                                                       Class-IX
                                                Subject-Chemistry
                                           Topic-Structure of an atom
                     Sub topic- Thomson’s model of an atom and its drawbacks
                OBJECTIVE QUESTIONS
                 Q.1     Assertion: Thomson’s model of an atom is based on electrons.
                         Reason: Thomson’s model of an atom is also called plum pudding model
                 Q.2     Assertion: Discovery of electrons was the basis of Thomson’s model of an atom.
                         Reason: Cathode rays are composed of negatively charged particles called electrons.
                 Q.3     Assertion:  In Thomson’s model of an atom the electrons are embedded in a

                         positively charged sphere.
                         Reason: The magnitude of positive and negative charges is equal.
                 Q.4     Assertion: Protons are positively charged particles.
                         Reason: Thomson named the positive charges as protons.
                 Q.5     Assertion: Thomson’s model of an atom was based on positive and negative

                         charges.
                         Reason: There was an experimental evidence.
                 Q.6     Who proposed the first model of an atom?
                         a) E. Goldstein        b) Bohr          c) J.J. Thomson                d) J. Chadwick
                 Q.7     Thomson’s model of an atom could give explanation for which particles?
                         a)     protons
                         b)     electrons
                         c)     neutrons
                         d)     positrons


               SUBJECTIVE QUESTIONS
            S.LNo.  Questions                                                                      Mark
            Q.1        Which sub atomic particle was discovered when Thomson proposed              1
                       his model of an atom?
            Q.2        How did Thomson realize that positive charges must also exist within        1
                       an atom?
            Q.3        Give the postulates of Thomson’s model of an atom.                          3

            Q.4        Thomson’s model of an atom is also called plum pudding model or             3
                       watermelon model? Give reasons.
            Q.5        What are the advantages and drawbacks of Thomson’s model of an              5
                       atom?












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