Molecular Spectroscopy

 

Electromagnetic Spectrum

Visible Spectrum

Electromagnetic Spectrum

Type of Radiation Frequency Range (Hz) Wavelength Range Type of Transition
gamma-rays 1020-1024 <10-12 m nuclear
x-rays 1017-1020 1 nm-1 pm inner electron
ultraviolet 1015-1017 400 nm-1 nm outer electron
visible 4-7.5x1014 750 nm-400 nm outer electron
near-infrared 1012-4x1014 2.5 um-750 nm outer electron molecular vibrations
infrared 1011-1012 25 um-2.5 um molecular vibrations
microwaves 108-1012 1 mm-25 um molecular rotations, electron spin flips*
radio waves 100-108 >1 mm nuclear spin flips*

*energy levels split by a magnetic field