KVPY Sample Paper KVPY Stream-SX Model Paper-22

  • question_answer
    In a decay series, \[_{82}^{206}Pb\] is obtained at the end from \[_{92}^{238}U.\] How many alpha and beta particles must have been emitted?

    A) \[7\alpha ,10\beta \]

    B) \[8\alpha ,6\beta \]

    C) \[5\alpha ,6\beta \]

    D) \[6\alpha ,8\beta \]

    Correct Answer: B

    Solution :

    \[\underset{92}{\mathop{238}}\,U\to \underset{82}{\mathop{206}}\,Pb\]
    Number of \[\alpha \]-particles
    \[=\frac{38}{4}=8\alpha \]
    Number of \[\beta \]-particles \[=2\times \] number of \[\alpha \]-particles - change in atomic number
    \[=2\times 8-\left( 92-82 \right)\]
    \[=16-10=6\beta \]

You need to login to perform this action.
You will be redirected in 3 sec spinner