Page 1 - 4.HOME ASSIGNMENT-(RUTHERFORD'S ALPHA PARTICLE SCATTERING EXPERIMENT & DISCOVERY OF NUCLEUS)
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SAI International School
                                                Subject-Chemistry

                                            Ch-Structure of the Atom
                    Topic- Rutherford’s alpha particle scattering experiment and
                                               discovery of nucleus

                OBJECTIVE QUESTIONS
                 Q.1     Assertion: In Rutherford’s gold foil experiment, very few α -particles are
                         deflected back.
                         Reason: Nucleus present inside the atom is heavy.
                 Q.2     Assertion: In Rutherford’s alpha particle scattering experiment most of the
                         alpha particles passed through the gold fail.
                         Reason: Atoms are extremely small.
                 Q.3     Assertion:  Electrons radiate energy when they move around the nucleus
                         in their orbits.
                         Reason: Electrons are in accelerated motion
                 Q.4     Assertion: Very few alpha particles bounced back.
                         Reason: The total mass of the atom is concentrated at the nucleus.
                 Q.5     Assertion: Atoms are stable.
                         Reason: The protons and neutrons are present inside the nucleus.
                 Q.6     Rutherford’s experiment which established the nuclear model of the atom used a
                         beam of
                             a)  Beta-particles which impinged on the metal foil and got absorbed
                             b)  Gamma rays which impinged on a metal foil and ejected electrons
                             c)  Hydrogen atoms, which impinged on a metal foil and got scattered
                             d)  Alpha-particles nuclei, which impinged on a metal foil and got scattered
                 Q.7     Which of the following does not represent alpha particle?
                                                2+
                                                                                             2+
                         a)     α              b)  α             c)   He 2-                 d)   He

               SUBJECTIVE
            S.LNo.  Questions                                                                      Mark
            Q.1        Which observation of Rutherford’s alpha particle scattering                 1
                       experiment proves that most of the space in an atom is empty?
            Q.2        What would have happened if Iron was chosen for Rutherford’s alpha          1
                       particle scattering experiment?
            Q.3        Why did Rutherford suggest that the positive charge in an atomic nucleus is   3
                       concentrated in a tiny region rather than spread evenly throughout the atom?
            Q.4        Why do scientists say the planetary model can’t be correct because the      3
                       electrons would collapse into the nucleus?

            Q.5        a) From Rutherford’sα-particle scattering experiment give the               5
                       experimental evidence for deriving the conclusion that
                              (i)    Most of the space inside the atom is empty.
                              (ii)   The nucleus of an atom is positively charged.
                       b) Why was Rutherford’s model of an atom called Planetary model? State
                       one drawback of his model of an atom.





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