JCECE Engineering JCECE Engineering Solved Paper-2008

  • question_answer
    The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

    A) \[III\]                                    

    B) \[IV\]

    C)  \[I\]                                     

    D)  \[II\]

    Correct Answer: A

    Solution :

    \[E=Rhc\left[ \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right]\]                 \[{{E}_{(4\to 3)}}=Rhc\left[ \frac{1}{{{3}^{2}}}-\frac{1}{{{4}^{2}}} \right]\]                 \[=Rhc\left[ \frac{7}{9\times 16} \right]=0.05\,\,Rhc\]                 \[{{E}_{(4\to 2)}}=Rhc\left[ \frac{1}{{{2}^{2}}}-\frac{1}{{{4}^{2}}} \right]\]                 \[=Rhc\left[ \frac{3}{16} \right]=0.2\,\,Rhc\]                 \[{{E}_{(2\to 1)}}=Rhc\left[ \frac{1}{{{(1)}^{2}}}-\frac{1}{{{(2)}^{2}}} \right]\]                 \[=Rhc\left[ \frac{3}{4} \right]=0.75\,\,Rhc\]                 \[{{E}_{(1\to 3)}}=Rhc\left[ \frac{1}{{{(3)}^{2}}}-\frac{1}{{{(1)}^{2}}} \right]\]                 \[=-\frac{8}{9}Rhc=-0.9\,\,Rhc\] Thus, transition III gives most energy. Transition I represents the absorption of energy.


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