| 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 | 1x1014-4x1014 | 2.5 um-750 nm | outer electron molecular vibrations |
| infrared | 1013-1014 | 25 um-2.5 um | molecular vibrations |
| microwaves | 3x1011-1013 | 1 mm-25 um | molecular rotations, electron spin flips* |
| radio waves | <3x1011 | >1 mm | nuclear spin flips* |