absorption spectrum

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absorption spectrum:

see spectrumspectrum,
arrangement or display of light or other form of radiation separated according to wavelength, frequency, energy, or some other property. Beams of charged particles can be separated into a spectrum according to mass in a mass spectrometer (see mass spectrograph).
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absorption spectrum

A spectrum that is produced when electromagnetic radiation has been absorbed by matter. Typically, absorption spectra are produced when radiation from an incandescent source, i.e. radiation with a continuous spectrum, passes through cooler matter. Radiation is absorbed (i.e. its intensity is diminished) at selective wavelengths so that a pattern of very narrow dips or of wider troughs – i.e. absorption lines or bands – are superimposed on the continuous spectrum.

The wavelengths at which absorption occurs correspond to the energies required to cause transitions of the absorbing atoms or molecules from lower energy levels to higher levels. In the hydrogen atom, for example, absorption of a photon with the required energy results in a ‘jump’ of the electron from its normal orbit to one of higher energy (see hydrogen spectrum).

The absorption lines (or bands) of a star are produced when elements (or compounds) in the outermost layers of the star absorb radiation from a continuous distribution of wavelengths generated at a lower level in the star. Basically the same elements occur in stars. Since each element has a characteristic pattern of absorption lines for any particular temperature (and pressure) range, there are several different types of stellar spectra depending on the surface temperature of the star. See spectral types. See also emission spectrum.

Absorption Spectrum

 

the spectrum that results when optical or X-radiation is passed through a substance and is selectively absorbed.

absorption spectrum

[əb′sȯrp·shən ‚spek·trəm]
(spectroscopy)
A plot of how much radiation a sample absorbs over a range of wavelengths; the spectrum can be a plot of either absorbance or transmittance versus wavelength, frequency, or wavenumber.
References in periodicals archive ?
As illustrated in Figure 2, illumination of PEA 1 in the presence of RB and oxygen clearly promoted changes in its emission and absorption spectra as well as its proton NMR and ESI-MS patterns.
In this work, the absorption spectra of HSA with various amounts of cisplatin recorded.
A selection of the analysed wavelengths in spectroscopic measurements is depended on a few factors, such as absorption spectrum of the given gas, optoelectronic elements availability of the desired spectral characteristics as well as absorption spectra of each gas in the mixture.
All absorption spectra in the UV/V region were obtained between 250 nm and 380 nm in quartz cuvettes (optic grade: 1.
Therefore, another pattern, in which each nanosphere faced six neighbor nanospheres, was simulated to observe the absorption spectra, as shown in Fig.
Absorption spectra were measured with an absorption spectrophotometer (Hitachi, U-3310).
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Fourier Transform Infrared Spectroscopy analysis results in an absorption spectra which provides information about the chemical bonds and molecular structure of a material.
Using sophisticated analytical instrument at the Advanced Light Source facility, they measured the absorption spectra of low-energy X-rays by carbon, nitrogen, and oxygen in the fossils.
Using spectrophotometer Shimadzu UV-1700 the electronic ground-state absorption spectra were recorded at the room temperature.
This corresponds to the absorption spectra of porphyrins, which are stimulated to produce free radicals and oxygen atoms (2).