Related topics: electrons

Visualizing cement hydration on a molecular level

The concrete world that surrounds us owes its shape and durability to chemical reactions that start when ordinary Portland cement is mixed with water. Now, MIT scientists have demonstrated a way to watch these reactions under ...

Novel SERS sensor helps to detect aldehyde gases

Prof. Huang Qing's group from the Hefei Institutes of Physical Science (HFIPS) developed a surface-enhanced Raman spectroscopy (SERS) gas sensor to detect aldehyde with high sensitivity and selectivity, which provided a new ...

The secret to stickiness of mussels underwater

Mussels survive by sticking to rocks in the fierce waves or tides underwater. Materials mimicking this underwater adhesion are widely used for skin or bone adhesion, for modifying the surface of a scaffold, or even in drug ...

A new method to better study microscopic plastics in the ocean

If you've been to your local beach, you may have noticed the wind tossing around litter such as an empty potato chip bag or a plastic straw. These plastics often make their way into the ocean, affecting not only marine life ...

Discovery of huge Raman scattering at atomic point contact

Nanofabrication of electronic devices has reached a single nanometer scale (10-9 m). The rapid advancement of nanoscience and nanotechnology now requires atomic-scale optical spectroscopy in order to characterize atomistic ...

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Spectroscopy

Spectroscopy was originally the study of the interaction between radiation and matter as a function of wavelength (λ). In fact, historically, spectroscopy referred to the use of visible light dispersed according to its wavelength, e.g. by a prism. Later the concept was expanded greatly to comprise any measurement of a quantity as function of either wavelength or frequency. Thus it also can refer to a response to an alternating field or varying frequency (ν). A further extension of the scope of the definition added energy (E) as a variable, once the very close relationship E = for photons was realized (h is the Planck constant). A plot of the response as a function of wavelength—or more commonly frequency—is referred to as a spectrum; see also spectral linewidth.

Spectrometry is the spectroscopic technique used to assess the concentration or amount of a given species. In those cases, the instrument that performs such measurements is a spectrometer or spectrograph.

Spectroscopy/spectrometry is often used in physical and analytical chemistry for the identification of substances through the spectrum emitted from or absorbed by them.

Spectroscopy/spectrometry is also heavily used in astronomy and remote sensing. Most large telescopes have spectrometers, which are used either to measure the chemical composition and physical properties of astronomical objects or to measure their velocities from the Doppler shift of their spectral lines.

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