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Jablonski diagram of an energy scheme used to explain the difference between fluorescence and phosphorescence. The excitation of molecule A to its singlet excited state ( 1 A*) may, after a short time between absorption and emission (fluorescence lifetime), return immediately to ground state , giving off a photon via fluorescence (decay time).
Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite . Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment.
Hence, the main functional application of Gibbs energy from a thermodynamic database is its change in value during the formation of a compound from the standard-state elements, or for any standard chemical reaction (ΔG° form or ΔG° rx). The SI units of Gibbs energy are the same as for enthalpy (J/mol).
The best known type is a copper-activated zinc sulfide (ZnS) and the silver-activated zinc sulfide (zinc sulfide silver). The host materials are typically oxides, nitrides and oxynitrides, [2] sulfides, selenides, halides or silicates of zinc, cadmium, manganese, aluminium, silicon, or various rare-earth metals. The activators prolong the ...
Figure 1: Reaction Coordinate Diagram: Starting material or reactant A convert to product C via the transition state B, with the help of activation energy ΔG ≠, after which chemical energy ΔG° is released. Qualitatively, the reaction coordinate diagrams (one-dimensional energy surfaces) have numerous applications.
Silver, added to zinc sulfide to produce a phosphor/scintillator used in radium dials, spinthariscopes, and as a common blue phosphor in color CRTs, and to zinc sulfide-cadmium sulfide used as a phosphor in black-and-white CRTs (where the ZnS/(Zn,Cd)S ratio determines the blue/yellow balance of the resulting white); short afterglow
The Ellingham diagram plots the Gibbs free energy change (ΔG) for each oxidation reaction as a function of temperature. For comparison of different reactions, all values of ΔG refer to the reaction of the same quantity of oxygen, chosen as one mole O (1 ⁄ 2 mol O 2) by some authors [2] and one mole O 2 by others. [3] The diagram shown ...
Jablonski diagram including vibrational levels for absorbance, non-radiative decay, and fluorescence. When a molecule absorbs a photon, the photon energy is converted and increases the molecule's internal energy level. Likewise, when an excited molecule releases energy, it can do so in the form of a photon.