Excited atoms return to their ground state in_______________?
Correct answer: B. 10-8s
- A. 10-10s
- B. 10-8s
- C. 10-6s
- D. 10-9s
Explanation
An excited atomic state usually has a lifetime of about 10^-8 s before spontaneous emission returns the atom to a lower state. This short lifetime follows from the probability of spontaneous photon emission. The likely mistake is choosing 10^-10 s, which is a timescale associated with some other atomic processes, not the usual excited-state lifetime.
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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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