Search results
Results From The WOW.Com Content Network
Brunauer, Emmett and Teller's model of multilayer adsorption is a random distribution of molecules on the material surface. Adsorption is the adhesion [1] of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. [2] This process creates a film of the adsorbate on the surface of the adsorbent.
A more general term is sorption, which covers absorption, adsorption, and ion exchange. Absorption is a condition in which something takes in another substance. [1] In many processes important in technology, the chemical absorption is used in place of the physical process, e.g., absorption of carbon dioxide by sodium hydroxide – such acid ...
Absorption "the incorporation of a substance in one state into another of a different state" [1] (e.g., liquids being absorbed by a solid or gases being absorbed by a liquid); Adsorption The physical adherence or bonding of ions and molecules onto the surface of another phase (e.g., reagents adsorbed to a solid catalyst surface); Ion exchange
This should not be confused with "absorbance". Spectral hemispherical absorptance: A ν A λ — Spectral flux absorbed by a surface, divided by that received by that surface. This should not be confused with "spectral absorbance". Directional absorptance: A Ω — Radiance absorbed by a surface, divided by the radiance incident onto that surface.
The absorption spectrum is primarily determined [2] [3] [4] by the atomic and molecular composition of the material. Radiation is more likely to be absorbed at frequencies that match the energy difference between two quantum mechanical states of the molecules .
The absorption of electromagnetic radiation by water depends on the state of the water. The absorption in the gas phase occurs in three regions of the spectrum. Rotational transitions are responsible for absorption in the microwave and far-infrared, vibrational transitions in the mid-infrared and near-infrared. Vibrational bands have rotational ...
The technique makes use of the atomic absorption spectrum of a sample in order to assess the concentration of specific analytes within it. It requires standards with known analyte content to establish the relation between the measured absorbance and the analyte concentration and relies therefore on the Beer–Lambert law.
The absorbance spectrum is plotted on a graph of absorbance vs. wavelength. [9] An Ultraviolet-visible spectroscopy#Ultraviolet–visible spectrophotometer will do all this automatically. To use this machine, solutions are placed in a small cuvette and inserted into the holder. The machine is controlled through a computer and, once it has been ...