Atoms & Nuclei

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56 of 239

Question 56 of 239

For hydrogen atom, λ1{\lambda }_{1} and λ2{\lambda }_{2} are the wavelengths corresponding to the transitions 11 and 22 respectively as shown in figure. The ratio of λ1{\lambda }_{1} and λ2{\lambda }_{2} is x32\dfrac{x}{32}. The value of xx is ______.

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Answer: 27

Wavelength corresponding to the photon emitted in transition n=3ton=1n=3ton=1 is
1λ1=R(112−132)=8R9\dfrac{1}{{\lambda }_{1}}=R\left(\dfrac{1}{{1}^{2}}-\dfrac{1}{{3}^{2}}\right)=\dfrac{8R}{9} ....(1)
Wavelength corresponding to the photon emitted for transition in transition
n=2ton=1n=2ton=1 is
1λ2=R(112−122)=3R4\dfrac{1}{{\lambda }_{2}}=R\left(\dfrac{1}{{1}^{2}}-\dfrac{1}{{2}^{2}}\right)=\dfrac{3R}{4} ....(2)
λ1λ2=3R4×98R=2732\dfrac{{\lambda }_{1}}{{\lambda }_{2}}=\dfrac{3R}{4}\times \dfrac{9}{8R}=\dfrac{27}{32}
Hence, the value of
x=27x=27.

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