A certain material is kept at very low temperature. It is observed that when photons with energies between 0.2 and 0.9 eV strike the material, only photons of 0.4 eV and 0.7 eV are absorbed. Next the...

A certain material is kept at very low temperature. It is observed that when photons with energies between 0.2 and 0.9 eV

strike the material, only photons of 0.4 eV and 0.7 eV are absorbed. Next the material is warmed up so that it starts to emit

photons. When it has been warmed up enough that 0.7 eV photons begin to be emitted, what other photon energies are also

observed to be emitted by the material? Explain briefly.