Q$4$ Rotational spectroscopy and Rigid Rotor:

$($a$)$ In the far infrared spectrum of hydrogen bromide $(H^{79}Br),$ there is

a series of lines separated by $16\mathrm{.}72c{m}^{-1}.$ Calculate the values of the

moment of inertia and the internuclear separation in $H^{79}Br.$

$($b$)$ The microwave spectrum of Potassium Iodide ${(}^{39}{K}^{127}I)$ consists of a

series of lines whose spacing is almost constant at $3634MHz.$ Calcu$-$

late the bond length of ${?}^{39}{K}^{127}$I.