Some material consisting of a collection of microscopic objects is kept at a high temperature. A photon detector capable of
detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 eV, 0.5 eV, 0.8 eV,
2.0 eV, 2.5 eV, and 2.8 eV. These are the only photon energies observed.
(a) Draw and label a possible energy-level diagram for one of the microscopic objects, which has 4 bound states. On the
diagram, indicate the transitions corresponding to the emitted photons. Explain briefly.
(b) Would a spring–mass model be a good model for these microscopic objects? Why or why not?
(c) The material is now cooled down to a very low temperature, and the photon detector stops detecting photon
emissions. Next a beam of light with a continuous range of energies from infrared through ultraviolet shines on the
material, and the photon detector observes the beam of light after it passes through the material. What photon
energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? Explain
briefly.