An electron in a hydrogen atom falls from n equals 3 to n equals 2. The energy of the emitted photon is about
Correct answer: A. 1.89 eV
- A. 1.89 eV
- B. 13.6 eV
- C. 10.2 eV
- D. 3.4 eV
Explanation
The n equals 3 level is at minus 1.51 eV and n equals 2 at minus 3.4 eV, so the difference is 1.89 eV, a red photon and the first line of the Balmer series. The value 10.2 eV belongs to the n equals 2 to n equals 1 transition, in the ultraviolet. Always subtract the two level energies rather than quoting either one alone.
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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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