The Spectrum and Molecular Effects Wavelength (h) Energy Molecular effects higher frequency cm kcal/mol shorter wavelength 10-9 gamma rays 106 107 X rays 104 ionization vacuum UV 102 10-5 near UV electronic transitions 10-4 visible 10 infrared 10-3 1 molecular vibrations (R) 102 101 microwave 10-4 rotational motion 102 lower frequency radio 10-6 104 nuclear spin transitions longer wavelength Chapter 12 5 The Spectrum and Molecular Effects => =>