VMMC VMMC Medical Solved Paper-2005

  • question_answer
    The half-life of radium is 1620 years and its atomic weight is 226 kg per kilomol. The number of atoms that will decay from its 1 gm sample per second will be :(Avogadros number \[N=6.023\,\times {{10}^{23}}\] atoms/mol)

    A) \[3.61\,\times {{10}^{10}}\]        

    B)        \[3.6\,\times {{10}^{12}}\]                   

    C)            \[3.11\,\times {{10}^{15}}\]        

    D)        \[31.\,1\times {{10}^{15}}\]

    Correct Answer: A

    Solution :

    From the formula \[\frac{dN}{dt}=\lambda N\]                                                      ?(i) and        \[\lambda =\frac{0.693}{{{T}_{1/2}}}\]                 \[=\frac{0.693}{1620\times 365\times 24\times 60\times 60}\]   ?(ii)                 and        \[N=\frac{6.023\times {{10}^{23}}}{226}\]                            ?(iii) Now from equations (ii) and (iii), putting the values of K and N in equation (i), we get \[\frac{dN}{dt}=\frac{0.693\times 6.023\times {{10}^{23}}}{1620\times 365\times 24\times 60\times 226}\] \[=3.61\times {{10}^{10}}\]


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