2. Solved Papers
  3. JEE Main & Advanced

JEE Main & Advanced AIEEE Solved Paper-2003

  • question_answer
    the half-life of a radioactive isotope is 3 h. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 h would be     AIEEE  Solved  Paper-2003

    A)                         \[4.0\] g              

    B)       \[8.0\] g                              

    C) \[12.0\] g                            

    D) \[16.0\] g   

    Correct Answer: A

    Solution :

    \[C={{C}_{0}}{{\left( \frac{1}{2} \right)}^{y}}\]                     \[y=\frac{Total\text{ }time}{{{T}_{1/2}}}=\frac{18}{3}=6\]                     \[{{C}_{0}}=256\,g\] \[\therefore \]      \[{{C}_{\left( undecayed \right)}}=256{{\left( \frac{1}{2} \right)}^{6}}=\frac{256}{64}=4\,g\]


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