Consider electromagnetic waves propagating in air. (a) Determine the frequency of a wave with a wavelength of (i) 5.0 km, (ii) 5.0 \mu \mathrm{m}5.0μm, (iii) 5.0 nm. (b) What is the wavelength (in meters and nanometers) of (i) gamma rays of frequency 6.50 \times 10^{21} \mathrm{Hz}6.50×1021Hz and (ii) an AM station radio wave of frequency 590 kHz?