Calculate the frequency in hertz and cm-1, as well as the energy in joules and electron volts of an x-ray photon with a wavelength of 4.55 angstroms.

wavelength L = 4.55*10^-8 cm

= 0.455*10^-9 m

frequency f = c/L
= 3.00^8 m/s/0.455*10^-9 m
= 6.59*10^17 Hz

Wave number w = 1/L = 2.198*10^9 m^-1

Energy = h f = _______

= _______ eV

You finish it. You need the exercise more than I do.