COMEDK · Physics · 28. Atomic Physics
The first emission of hydrogen atomic spectrum in Lyman series appears at a wavelength of
- A \(\dfrac{7 R}{144} \mathrm{~cm}^{-1}\)
- B \(\dfrac{4}{3 R} \mathrm{~cm}\)
- C \(\dfrac{3 R}{4} \mathrm{~cm}^{-1}\)
- D \(\dfrac{400}{9 R} \mathrm{~cm}\)
Answer & Solution
Correct Answer
(B) \(\dfrac{4}{3 R} \mathrm{~cm}\)
Step-by-step Solution
Detailed explanation
The Rydberg formula for the hydrogen spectrum is given by \(\dfrac{1}{\lambda} = R \left( \dfrac{1}{n_1^2} - \dfrac{1}{n_2^2} \right)\), where \(R\) is the Rydberg constant. For the Lyman series, the transition occurs to the ground state, so \(n_1 = 1\). The first emission line…
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