The full width at half maximum of an atomic absorption line at 589.0 nm is 100 MHz. A beam of light passes through a gas with an atomic density of 1x10¹⁷ m^-3.

iCalculate the peak absorption coefficient due to this absorption line

iiCalculate the frequency at which the resonant contribution to the refractive index is at a maximum iii) Calculate the peak value of the resonant contribution to the refractive index

You can assume that the index of refraction n =1 in for this dilute gas.