Absorption Spectroscopy
Absorption-Spectroscopy refers to a suite of analytical techniques that measure the reduction in intensity of Electromagnetic-Radiation as it passes through a medium. This phenomenon occurs when Photons are absorbed by atoms or molecules, causing a transition from a ground state to an excited state. The quantitative relationship between the concentration of a substance and the amount of light absorbed is defined by the Beer-Lambert-Law, which is central to the field of Analytical-Chemistry. Detailed documentation on spectroscopic standards can be found through the National-Institute-of-Standards-and-Technology.
Core Methodologies
The specific region of the spectrum used determines the type of information obtained. UV-Vis-Spectroscopy is commonly used to study electronic transitions in molecules, while Infrared-Spectroscopy is employed to observe vibrational modes. For elemental analysis, Atomic-Absorption-Spectroscopy is a standard method for detecting metals in environmental and biological samples. These processes are deeply rooted in Quantum-Mechanics, as the energy of the radiation must precisely match the energy gap between states. Technical definitions and nomenclature are maintained by the International-Union-of-Pure-and-Applied-Chemistry.
Practical Applications
In Astronomy, Absorption-Spectroscopy is used to identify the chemical composition of stellar atmospheres by analyzing absorption lines in the observed light. In industrial settings, it is used for quality control and monitoring chemical reactions in real-time. The instrumentation typically involves a light source, a Monochromator to isolate specific wavelengths, and a detector to measure the transmitted light intensity. Additional resources on the history and development of these techniques are available at Encyclopedia Britannica and Wikipedia.