When we excite some atoms by heat collision or electrical discharge they will________________?
Correct answer: C. radiate electromagnetic energy of discrete characteristic wavelength
- A. radiate electromagnetic energy with a continuous distribution of wavelength
- B. absorb particular wavelengths when white light is incident on them
- C. radiate electromagnetic energy of discrete characteristic wavelength
- D. emit either invisible or visible light
Explanation
Excited atoms return to lower energy levels by emitting photons whose energies equal the differences between allowed levels. Since only particular energy differences are possible, the emitted radiation has discrete characteristic wavelengths. The likely mistake is choosing a continuous distribution, which is associated with thermal or other continuous sources rather than isolated atomic transitions.
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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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