JEE Main & Advanced Chemistry Surface & Nuclear Chemistry / भूतल और नाभिकीय रसायन Question Bank Causes of radioactivity and Group displacement law

  • question_answer
    The number of a and b -particles emitted during the transformation of \[_{90}T{{h}^{232}}\] to \[_{82}{{P}^{208}}\] are respectively   [MNR 1978; NCERT 1984;CPMT 1989; RPET 1999; MP PMT  2001; KCET 2003]

    A)                 4, 2        

    B)                 2, 2

    C)                 8, 6        

    D)                 6, 4

    Correct Answer: D

    Solution :

           \[_{90}T{{h}^{232}}\to {{\,}_{82}}P{{b}^{208}}+x{{\,}_{2}}H{{e}^{4}}+y{{\,}_{-1}}{{\beta }^{0}}\]                    Equating mass no.                    232 = 208 + 4x + 0 y or 4x = 24 or x = 6                    Equating atomic no.                    90 = 82 + 2x ?y or 90 = 82 + 2 × 6 ? y or \[y=4\]                                 Hence \[6\alpha \] and \[4\beta \] particles will be emitted. 


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