Atomic silver

If n — 1 photons are absorbed as in equation 8, then the complete annihilation of the -atom silver center can occur as shown in equations 12 and 13 ... 

Ozin and Huber 112) synthesized and characterized very small silver particles, Ag n = 2-5) by conventional deposition methods, as well as by a novel technique that they have termed "cryophotoaggrega-tion. This study will be discussed in detail in Section III. Of interest here is a study of silver atoms and small, silver clusters entrapped in ice and high-molecular-weight paraffin (n-C22H46, n-C32Hg8) matrices 146) (see Figs. 7 and 8, and Tables IV and V). Besides the intriguing, multiple-site (solvation) occupancy of atomic silver in ice matrices, and their thermal and photochemical interconvertibility, their extremely... 

The photochromic lenses contain a thin layer of a silver-containing glass, the silver being in its +1 oxidation state. Absorption of a photon supplies the energy for an electron-transfer reaction in the glass, the product of which is atomic silver ... 

Diez I, Ras RHA (2010) Few atom silver clusters as fluorescence reporters. In Demchenko AP (ed) Advanced Fluorescence Reporters in Chemistry and Biology II. Springer Ser... 

In general, silver clusters in solution are prepared by reduction of silver ions. Proper scaffolds, e.g., DNA, proteins, dendrimers and polymers, are essential to prevent the aggregation of clusters to larger nanoparticles. Although it is clear that the emission originates from few-atom silver clusters, many aspects of this exciting class of nanoscopic metals are not yet fully understood. 

Atomic silver forms in illuminated regions of the film, and hence the dark colour silver does not form in regions of the film shielded from light, which is why a photographic negative remains colourless in the dark. 

Polishing with an abrasive paste removes both the thin layer of tarnish and some silver atoms. Silver-plated pieces are therefore susceptible to losing their thin coating of silver. The aluminum method, by contrast, restores the silver lost to the tarnishing. 

Trade names Chemical formula silver atom silver colloidal sllflake sllpowder sllber No data Ag Grayson 1983 ... 

Second, the Cu2+ ion thus formed reacts with atomic silver formed in light to convert it back to silver ion in the absence of light ... 

The second example is the analysis of silver zeolite [7], in which it was shown that there is a substantial silver atom flux accompanying the relatively weak silver cation flux. There were no molecules or clusters containing silver in the gas phase. Pure silver metal heated to the sublimation point gives primarily neutral atoms and metallic clusters with no ions. Thus, sublimation of atomic silver ions from zeolite may be a pseudo-S-L type of process, although additional evidence concerning the species of silver in the solid state would be required prior to making this assertion. 

Silver species have been studied in a variety of A-zeolites including Nai2-A, K -A, Li -A, CsyNas-A and Cag-A (11). Complete exchange of cesium ion for sodium ion cannot be achieved in the A-zeolites. Typically the major cation was exchanged by silver to an extent of about 0.7 ion per unit cell which is 6% of the exchangeable cations. After irradiation about 0.003 silver ions per unit cell were converted to atomic silver species. 

Figure 7. The DFT calculated interaction of I-epoxy-3-butene (EpB) with a seven-atom silver cluster. [Adapted from (46)].

The following entropy values at 25 were obtained from thermal measurements silver, 10.3 cal./deg. per g.-atom silver chloride, 23.4 per mole liquid mercury, 17.8 per g.-atom and mercurous chloride, Hg2Cl2, 46.4 per mole. The increase in heat content of the reaction... 

Another possibility that could explain Lith development is the apparently contradictory phenomenon of bleach enhanced fog or BEF [70]. In this case compounds known as silver bleaches can cause fog in grains with sub-developable silver centers. Two-atom silver centers cannot initiate development and would be bleached by oxidants, for example, benzoquinone, to a one-atom silver center. A single silver atom is thermally unstable and can dissociate, without the need for an oxidant, into a silver ion and a mobile conduction-band electron. If several two-atom centers are present on a grain, a developable center can arise from the accumulation of these mobile electrons at a suitable site. 

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