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In Li^{++},electron in first Bohar orbt is excited to a level by a radiation of wavelength \lambda. When the ion gets deexited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of \lambda?

\left ( Given : h=6.63\times 10^{-34}js\, ;c=3\times 10^{8}ms^{-1} \right )

 

 

                                            

                                            

 

 

 

 

  • Option 1)

    11.4nm

  • Option 2)

    9.4nm

  • Option 3)

    12.3nm

  • Option 4)

    10.8nm

 

Answers (1)

best_answer

Possible\, \, emission= 6

\frac{n\left ( n-1 \right )}{2}=6\Rightarrow n=4n=4....................-0.85\times 9ev

                                             n=3....................

                                             n=2...................

                                            n=1......................-13.6\times 9ev

\Rightarrow \Delta E=\frac{hc}{\lambda }

\Rightarrow 13.6\times 9-0.85\times 9=\frac{hc}{\lambda }

\Rightarrow \lambda =\frac{hc}{9\times \left ( 13.6-0.85 \right )}

\Rightarrow \lambda =10.8nm


Option 1)

11.4nm

Option 2)

9.4nm

Option 3)

12.3nm

Option 4)

10.8nm

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Plabita

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