A spectrum is a plot of electromagnetic energy as a function of frequency or wavelength. The recording and studying of spectrum of energy levels in atoms or molecules in the physical sciences is called spectroscopy. A device for recording a spectrum is a spectrometer or spectrophotometer. The latter term is used when an optical spectrum is recorded by the device.
Types of spectroscopy
- Auger electron spectroscopy - The analysis of the energies of the stimulated emission of Auger electrons
- electromagnetic spectroscopy - The study electomagnetic radiation spectra given off or absorbed by atoms or molecules changing energy levels.
- infra-red spectroscopy - The study of spectra showing infra-red radiation absorbed by atoms or molecules making them vibrate.
- mass spectrometry - The study of the mass of molecules or atoms, measured by how much they bend as they are exposed to a magnetic field
- Mossbauer Spectroscopy - Measures the absorption of gamma-rays by atoms bound in a solid as a function of gamma-ray energy.
- Nuclear Magnetic Resonance - Measures the resonant absorption of RF radiation by nuclei in a strong magnetic field. Absorption peaks correspond to transitions in the nuclear spin states of the nuclei.
- Raman spectroscopy The study of spectra caused by the scattering and change in frequency of light due to the transition between vibrational/rotational energy levels in molecules.
- X-ray photoelectron spectroscopy
- Rotational spectroscopy
- Vibrational Spectroscopy
- Electron Spin Resonance Spectroscopy
- Fourier Transform Spectroscopy - An efficient method for collecting various spectra. Frequently applied to infra-red spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy.
- See also: spectroscopic analysis