Find the ratio of the number of atoms of gaseous sodium in the state 3P to that in the ground state 3S at a temperature T==2400K. The spectral line corresponding to the transition 3P→→3S is known to have the wavelength λ=589nm.
6.126.N˙/N0=(g/g0)e−ℏω/hT=1.14⋅10−4,where g and g0 are the statistical weights (degeneracy ratios) of the levels 3P and 3S respectively (g=6,g0=2)