10°m 10m Low frequency 103 03 Very high tHeesionl Ultra-high frequency (月adar X Rays Radio Waves 0.1 Ultra Violet Infta Red 10-2cn 0.4A 40A 4000A 40um 0.4cm 40cm 40m 103 cm 10-4cm Visible Ultraviolet 10-5cm 10-6cm 10-7cm X rays 10-8cm Gamma rays 109cm 10-0cm 10-1cm Cosmic rays 10-2cm Figure 11.1.Electromagnetic spectrum