The uncertainty principle can be used to estimate time and frequency scales governing optical transitions. make estimates for the following: (i) calculate the percentage uncertainty in the frequency ? ? /? of the emitted light when a hydrogen atom makes a transition from the fourth excited state to the ground state when the lifetime of the fourth excited state is ? -2.75 10.9 s. (ii) what is the lifetime of the ground state? give the reason for your answer. ii) a laser pulse has a linewidth defined as the uncertainty in the output (the spectral ine) wavelength ax. find an expression relating the linewidth of the laser's spectral line to the bandwidth which is the uncertainty in the frequency of the spectral line. (iv) if the duration of the laser pulse in ii) is 1.5 x 10-9 s, estimate the linewidth of the 632.8 nm beam from a hene laser.