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Compound atomic-level view

The atomic-level view shows the arrangement of sodium ions (Na ) and chloride ions (Cl ) in the ionic compound sodium chloride. The photo shows solid sodium chloride highly magnified. [Pg.81]

You know that when sodium and chlorine are mixed, a reaction occurs and a compound, sodium chloride, forms. The photograph at the beginning of this chapter showed the macroscopic view of this reaction. What can be happening at the atomic level Begin by picturing a collision between a sodium atom and a chlorine atom. Locate these atoms on the periodic table. Sodium is in Group 1, so it has one valence electron. Chlorine is in Group 17 and has seven valence electrons. [Pg.133]

The authors feel that compounds need to be sufficiently complex in order to provide a significant level of information content. On the other hand, compounds that are too complex may be viewed as undesirable. A number of measures for characterizing molecular complexity have been developed over the years. Complexity has been defined in terms of size, elemental composition, topology, symmetry, and functional groups present in a molecule (17,18). In the present work, we have applied a simple, chemically intuitive measure developed by Barone and Channon (18). This approach is based on a simple additive model, where values are assigned to specific classes of molecular features such as the types of atoms and bonding patterns, and the number and types of rings. This is illustrated in Eq. 2.1 ... [Pg.117]

The P-P band is ahrnys filled, corresponding 10 a P—P bond (225 pm) in the copper compound. At the other extreme, the P-P band it also filled, giving an antibonding interaction in addition. Thus, overall, there is a nonhonded interaction between the two phosphorus atoms and so we should not be surprised that the P-P distance is approximately twice the van der Waats radius or phosphorus (2 x 185 pm 384 pm) We can view the progression from Mn to Cu as a redox tuning of the occupancy of these energy levels 38... [Pg.689]

Substitution of the chloro atom by bromine, by fluorine, by nitrilo-, hydrazion-, alkyl-, haloalkyl-, alkoxyalkoxy groups leads very often to remarkable herbicidal but seldom -from the practical point of view - to superior activity. It is thereby obvious to everybody active in this field that the qualification superior activity can never relate to one parameter alone activity against the target organisms is, of course, an absolute prerequisite but this activity can, outside the field of industrial weed control, only be made valuable by a complementary suitable crop selectivity pattern. The following compounds resulting from our project reached the level of practical use ... [Pg.18]

If one analyzes the rotation of D-a-(methylenecyclopropyl)glycine (82) the optical activity must come from (at least) four sources. One rotation contribution is associated with the atomic asymmetry of the open-chain moiety (methylenecyclopropane being viewed as a ligand). On the other hand, optical activity will also be induced by the asymmetric carbon atom of the ring and the asymmetry in the electron density distribution of the exocyclic double bond system (with diastereotopic faces). Finally also helix optical activity may be operative. The example of 82 demonstrates the complexity of the optical rotation of an apparently simple cyclopropane derivative. Further discussions of optical rotations of similar compounds, therefore, will cling to only the qualitative level. [Pg.50]


See other pages where Compound atomic-level view is mentioned: [Pg.86]    [Pg.93]    [Pg.93]    [Pg.269]    [Pg.460]    [Pg.23]    [Pg.1862]    [Pg.657]    [Pg.81]    [Pg.600]    [Pg.420]    [Pg.188]    [Pg.431]    [Pg.127]    [Pg.390]    [Pg.451]    [Pg.56]    [Pg.892]    [Pg.1466]    [Pg.200]    [Pg.43]    [Pg.46]    [Pg.28]    [Pg.550]    [Pg.107]    [Pg.74]    [Pg.194]    [Pg.289]    [Pg.216]    [Pg.273]    [Pg.233]    [Pg.254]    [Pg.169]    [Pg.829]    [Pg.154]    [Pg.892]    [Pg.89]    [Pg.435]    [Pg.277]    [Pg.95]    [Pg.186]    [Pg.508]    [Pg.659]   
See also in sourсe #XX -- [ Pg.93 , Pg.94 ]




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