An absorption spectrum is produced when
Correct answer: B. white light passes through a cooler gas, which removes photons of its own characteristic energies
- A. a hot gas emits light
- B. white light passes through a cooler gas, which removes photons of its own characteristic energies
- C. light passes through a vacuum
- D. a solid is heated until it glows
Explanation
Atoms in the cooler gas absorb exactly the photon energies that match their own energy level differences, leaving dark lines in the continuous background at those wavelengths. The dark lines therefore fall at the same positions as the bright lines the same gas would emit when hot. Fraunhofer lines in sunlight are produced this way by the Sun's own atmosphere.
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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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