ATOM AND VALENCE ELECTRON SIGNALS –X-RAYS –GAMMA-RAYS

Radiation / E range / What can it do
γ-rays / 0.1 to 0.0001 nm / Can promote or remove inner (core) electrons
x-rays / 50 to 0.1 nm / Can promote or remove inner (core) electrons
Vacuum UV / 10-190 nm / Can break molecular bonds. Results in the removal or promotion of electrons to excited states
UV / 190-300 nm / Can break molecular bonds. Results in the removal or promotion of electrons to excited states
Visible / 350 to 800 nm / Results in the removal or promotion of electrons to excited states
IR / 0.8-300 μm / Increases the amplitude of vibrations
Microwaves / ~1-4 mm / Increases the rate of molecular rotation

WHAT ATOM CAN SAY TO US?

Infrared
(outer electrons and/or valence electrons) / Infrared Spectroscopy is the analysis of infrared light interacting with a molecule. This can be analyzed in three ways by measuring absorption, emission and reflection. / The main use of this technique is in organic and inorganic chemistry. It is used by chemists to determine functional groups in molecules. IRSpectroscopy measures the vibrations of atoms, and based on this it is possible to determine the functional groups. Generally, stronger bonds and light atoms will vibrate at a high stretching frequency (wavenumber).
UV-Vis-NIR
(outer electrons and/or valence electrons) / UV/Vis spectroscopy is routinely used in analytical chemistry for the quantitative determination of different analytes, such as transition metal ions, highly conjugatedorganic compounds, and biological macromolecules. / Refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet-visible spectral region. This means it uses light in the visible and adjacent (near-UV and near-infrared [NIR]) ranges. The absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved. In this region of the electromagnetic spectrum, molecules undergo electronic transitions. This technique is complementary to fluorescence spectroscopy, in that fluorescence deals with transitions from the excited state to the ground state, while absorption measures transitions from the ground state to the excited state.
X rays
(inner electrons) / The most abundant is X-ray emission spectroscopy. It is routinely used for qualitative and quantitative analysis of inorganic materials. There are two types of X-ray emission spectroscopy:
  • Energy-dispersive X-ray spectroscopy (EDS), and
  • Wavelength dispersive X-ray spectroscopy (WDS).
/ When an electron from the inner shell of an atom is excited by the energy of a photon, it moves to a higher energy level, which is shown as an outer shell; the difference in energy is emitted as a photon which has a wavelength that is characteristic for the element (there could be several of characteristic wavelengths per element). Analysis of the X-ray emission spectrum produces qualitative results about elemental composition of the specimen. Comparison of spectrum of the specimen with spectra of standards of known composition produces quantitative results (after some mathematical corrections for absorption, fluorescence and atomic number).
Gamma rays
(from atom nucleus) / Gamma spectroscopy is the science of identification and/or quantification of radionuclides by analysis of the gamma-ray energy spectrum produced in a gamma-ray spectrometer. It is a widely used technique. / Most radioactive sources produce gamma rays, which are of various energies and intensities. When these emissions are detected and analyzed with a spectroscopy system, a gamma-ray energy spectrum can be produced. A detailed analysis of this spectrum is typically used to determine the identity and quantity of gamma emitters present in a gamma source, and is a vital tool in radiometric assay. The gamma spectrum is characteristic of the gamma-emitting nuclides contained in the source, just as in optical spectroscopy, the optical spectrum is characteristic of the material contained in a sample.
Gamma-ray spectroscopy is the quantitative study of the energy spectra of gamma-ray sources, in such as the nuclear industry, geochemical investigation, and astrophysics.
Spectroscopy
Infrared /
  • FT-IR
  • Raman
  • Rotational
  • Vibrational

UV-Vis-NIR /
  • Ultraviolet-visible
  • Fluorescence
  • Vibronic
  • Near-infrared
  • Laser-induced

X-ray and
Photoelectron /
  • Photoelectron
  • Atomic
  • Emission

Nucleon /
  • Gamma
  • Mössbauer

Radiowave /
  • NMR
  • Terahertz
  • ESR/EPR
  • Ferromagnetic resonance

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