The decay of excited states in atoms and nuclei often leave the system in another, albeit lower-energy, excited state. 

(a) One example is the decay between two excited states of the nucleus of Ti. The upper state has a lifetime of 1.4 ps, the lower state 3.0 ps. What is the fractional uncertainty ΔE/E in the energy of 1.3117 MeV gamma rays connecting the two states? 

(b) Another example is the Ha line of the hydrogen Balmer series. In this case the lifetime of both states is about the same, 10^-8 s. What is the uncertainty in the energy of the H_a photon?