Absorption Definition and 534 Threads

Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum.
Absorption spectroscopy is employed as an analytical chemistry tool to determine the presence of a particular substance in a sample and, in many cases, to quantify the amount of the substance present. Infrared and ultraviolet–visible spectroscopy are particularly common in analytical applications. Absorption spectroscopy is also employed in studies of molecular and atomic physics, astronomical spectroscopy and remote sensing.
There are a wide range of experimental approaches for measuring absorption spectra. The most common arrangement is to direct a generated beam of radiation at a sample and detect the intensity of the radiation that passes through it. The transmitted energy can be used to calculate the absorption. The source, sample arrangement and detection technique vary significantly depending on the frequency range and the purpose of the experiment.
Following are the major types of absorption spectroscopy:

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  1. L

    Absorption and Spectroscopy: Why increased counts at lower energies?

    Hi! In my lab class, we are using a photomultiplier to examine gamma ray emission lines and determine absorption coefficients of different radioactive materials. Homework Statement As we test for absorption (by layering on metals, incrementally increasing the thickness), we consider spectral...
  2. Z

    Photon absorption - Newton vs. Einstein

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  3. S

    Can Free Fundamental Particles Absorb Photons?

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  4. H

    Indirect absorption and phonons

    In an indirect absorption process that an electron jumps from the top of the valence band to the bottom of the conduction band,why a phonon must be involved to conserve the momentum? At these two points (top of the valence band and bottom of the conduction band) the electron momentum is zero so...
  5. P

    Best material for IR absorption

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  6. S

    Thermodynamics: Heat absorption / rejection vs colour

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  7. J

    Callen & Welton calculation of power of absorption

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  8. W

    Absorption with UV/VIS spectrometer

    I need to characterize some colloids (extract the concentration of material inside). Why should I dilute the sample before measuring it with spectrometer?
  9. V

    Absorption band and absorption peak?

    The absorption spectra of some materials appear as the absorption bands (for example: TiO2 powder) while the other appear as the absorption peaks (for example: Quantum dots). Please explain why they are different?
  10. S

    Spectral lines and absorption lines

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  11. M

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  12. A

    Absorption prob - why my way isn't correct?

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  13. C

    Need help manipulating absorption spectroscopy data please

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  14. MikeGomez

    Is photon phase a factor in absorption

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  15. jaumzaum

    Radiation absorption by an atom

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  16. A

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  17. M

    Markov Chains and absorption probabilites

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  18. M

    Markov Chains and absorption probabilites

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  19. S

    Free carrier absorption in GaSb

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  20. I

    Evidence of single photon absorption?

    Hey all, Does anyone know of a paper or experiment that verified that a single photon is absorbed in exchange for electron excitation? Thanks
  21. J

    Understanding molecular absorption of light (UV-Vis spectroscopy)

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  22. W

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    can anyone give an example in which a nucleus absorbs a neutron and becomes a stable nucleus? or the combination must break into parts?
  23. L

    How Do You Calculate the Percentage Transmission Using the Beer-Lambert Law?

    An aqueous solution of yeast nucleic acid of length 2.0*10^-2m and concerntrated 2.0mol m-3 has an absorptivity of 25m2 mol-1 at a certain wavelenght. calculate the percentages tranmission at this wavelenght. this is an example that i don't understant, please help me to simplify it and...
  24. H

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  25. F

    Quantum dots:emission versus absorption spectrum

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  26. R

    Finding Vibrational Spacing from Fluorescence and Absorption Spectre

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  27. P

    Finding a light source that produces an absorption spectrum?

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  28. D

    Maximizing heat absorption through Radiation

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  29. P

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  30. A

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  31. R

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  32. B

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  33. N

    Photon absorption and momentum recoil

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  34. S

    Mass Absorption -V- Black Hole size

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  35. F

    Spin statistic terms in absorption cross section

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  36. B

    How to Determine Band Gap of Amorphous Materials Using Optical Absorption Edge

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  37. K

    Understanding RF Absorption by Metals in RFID Testing

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  38. J

    Long vs Short light wavelength absorption

    Hi all I was reading through an astrophysics book{1} and there I came across this sentence: " A dust cloud can either scatter or absorb light that passes through it. Since shorter wavelengths are affected more significantly than longer ones, a star lying behind the cloud appears reddened...
  39. A

    Radio wave attenuation and scattering and absorption

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  40. K

    The color of an apple (light absorption and emission)

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  41. T

    Question about absorption spectra

    Been viewing this site for a while now and very much appreciate all the contributors! I can't seem to find an answer to this anywhere so I think I may be misunderstanding the basic ideas of absorption and emission spectra... An absorption spectrum, say of our Sun, is as I understand it the...
  42. P

    Absorption and Emission Spectrum

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  43. A

    Does Fresnel reflection involves absorption of light?

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  44. J

    Glass that has minimum reflection and absorption at 1550nm

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  45. C

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  46. C

    Neutron Absorption of Lead Nuclei compared to Uranium Nuclei

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  47. K

    UV light absorption by transparent sheets – how?

    Ok thanks for the responses to my other question; I think I now have it. I have a follow up question – that is almost on the same topic (but not quite) The complete spectrum (arund 200nm to 380nm) of UV light is absorbed by some plastics?? Elections will be moved to a more energetic orbital...
  48. D

    Colours of objects produced by light due to reflection & absorption

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  49. A

    Calculating Absorption Coefficient

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  50. E

    Absorption coefficient of quantum well

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