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The longest wavelength radiations in Paschen series have wavelength equal to:

Correct answer: D. Option D

  • A. Option A
  • B. Option B
  • C. Option C
  • D. Option D

Explanation

The Paschen series includes all transitions that end at level n = 3. The longest wavelength happens when the electron loses the least energy. The smallest drop is from n = 4 to n = 3, since these levels are closest. A smaller energy drop means a longer wavelength photon. So, the longest wavelength in the Paschen series is from the 4 → 3 transition and equals 144/7R.

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About Atomic Spectra

Atoms emit or absorb light at specific wavelengths because electrons occupy quantized energy levels and change levels by absorbing or releasing photons. The topic covers emission and absorption spectra, spectral series, hydrogen’s line spectrum, energy-level transitions, and the relation between wavelength, frequency and photon energy.

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