Quantum Quantum Mechanics Spectroscopy Questions

I’m working on a physics multi-part question and need an explanation to help me study.

1. The degeneracy ratio of the energy levels is important in microwave spectroscopy. What is the degeneracy of the third excited rotational level? [ Select ] [“7“, “1“, “3“]

2. The typical energy difference for transitions in electronic spectroscopy is 5 x 10-18 J. Calculate the ratio of the number of molecules in two adjacent levels, the ground and the first excited level, at 300 K. Assume the electronic states are singlets. [ Select ] [“approximately 0“, “7.4 x 10^(-22)“, “7.4 x 10^(-5)“]

3. Considering the ratio of molecules in the ground level to the first excited level in microwave spectroscopy (MW) and in electronic spectroscopy (EL), select the incorrect statement. [ Select ] [“The ratio for EL is smaller than 1“, “The ambient temperature does not affects the ratio in MW“, “The ratio for MW is larger than 1“]