The lifetime of the 32P1/2 to 32S1/2 transition of the Na atom at 5896 angstrom (one of the Na D lines) is measured to be 16.4 ns. What are the einstein a and b coeff? What is the transition moment in debye? What is the peak absorption cross section for the transition in angstrom2, assuming that the linewidth is determined by lifetime broadening. I'm really at a loss where to start here. I know B1<-0=(2∏2/3εoh2)μ102, where μ is the transition moment. Similarly, I have an equations for A in terms of frequency and μ. How do I solve for μ? What about the last part?