2. The five lowest energy levels of a certain atomic gas have the values E₁ = 0, E2 = 3.80 eV, E3= 4.30 eV, E4 = 7.2 eV, and E5 = 7.5 eV. (a) If the temperature is high enough that all levels are occupied and the gas is illuminated with light of wavelength 2400 nm, what transitions can occur? (b) Which of the transitions you found in part (a) will still occur if the temperature is so low that only the state E₁ is occupied? (c) What wavelength of the incident light would stimulate emission from the state Е₁?

2. The five lowest energy levels of a certain atomic gas have the values E₁ = 0, E2 = 3.80 eV, E3= 4.30 eV, E4 = 7.2 eV, and E5 = 7.5 eV. (a) If the temperature is high enough that all levels are occupied and the gas is illuminated with light of wavelength 2400 nm, what transitions can occur? (b) Which of the transitions you found in part (a) will still occur if the temperature is so low that only the state E₁ is occupied? (c) What wavelength of the incident light would stimulate emission from the state Е₁?