Question

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Q). When is $H_{\alpha }$ line in the emission spectrum of hydrogen atom obtained? Calculate the frequency of the photon emitted during this transition.

Answer 1

Dear student
When the electron falls from third energy level to the second energy level then we find the H-alpha line

i.e.n = 3 to n = 2 is called Balmer-alpha or H-alpha,

$$\begin{gathered} ForBalmerseries,frequencyisgivenby: \\ \frac{\nu }{c}=R\left(\frac{1}{2^2}-\frac{1}{n^2}\right) \\ where\nu isthefrequency,cisthespeedoflight,Risrydbergcons\tan t. \\ forfirstline,n=3 \\ \nu =Rc\left(\frac{1}{2^2}-\frac{1}{3^2}\right) \\ \nu =1.097\times {10}^7\times 3\times {10}^8\left(0.25-0.11\right) \\ \nu =0.46\times {10}^{15}Hz \end{gathered}$$


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