Three-dimensional sketching

Figure 13 Three-dimensional sketch of leaching pattern for chloride, ammonium, and NVOC from Grindsted...

Fig. 14.1. Three-dimensional sketch (a) and cross-section view (b) of an NMOSFET, with an enlarged cross section to show the triangle encompassed by ABC (c) for Yau s model...

The structure of the water molecule, (a) A three-dimensional sketch, (b) Angular water structure, (c) The H—O—H bond angle In water. 

In three-dimensional sketching, sketched objects show width, height, and depth. 

Three-dimensional sketching is the quickest way to convey ideas to others. It also is the least likely method to create misunderstanding. Remember from Chapter 4 clear communication is most important to the design process. 

Determine the geometry around each interior atom in the glycine structure and make a three-dimensional sketch of the molecule. 

Learning to form three-dimensional mental models of molecules and polyatomic ions is a skill you should develop while studying this chapter. The Lewis diagram is a convenient two-dimensional paper-and-pencU representation of the distribution of electrons in a molecule, but it has limited information. A goal to work toward is to be able to look at a Lewis diagram and then see a model of that species in your mind. Our emphasis on three-dimensional ball-and-stick diagrams in the examples that follow and in the end-of-chapter questions is meant to help you make the connection between Lewis diagrams and these mental models. If you have a molecular model kit, your models and the three-dimensional sketches you draw should match. 

Finally, draw a three-dimensional sketch of the molecule. 

Now draw the three-dimensional sketch. Recall that all atoms with a trigonal planar electron-pair geometry lie in the same plane. Assume that all six atoms are in the same plane, which they are. 

Figure 7-9 (Continued) (e) Three-dimensional sketch of contour envelope for and (f) for ij/-.

The whole set of operations produces an axial molecule in which there are four equivalent substituents at either end. The black and white points are at different distances from the axis, and so the radii of the circles drawn to show the relationship between images in Figure 3.6a are different, emphasizing that there are no symmetry-equivalent points at opposite ends of the object. Below the three-dimensional sketch is a plan view of the same structure. For the points at either end of the object, we could also think to introduce vertical mirror planes relating the points to their opposite images within the same terminal group. However, the offset in orientation between the two ends is such that these mirror planes would not be symmetry elements of the object as a whole. 

Write orbital diagrams (boxes with arrows in them) to represent the electron configurations— without hybridization—for all the atoms in PH3. Circle the electrons involved in bonding. Draw a three-dimensional sketch of the molecule and show orbital overlap. What bond angle do you expect from the unhybridized orbitals How well does valence bond theory agree with the experimentally measured bond angle of 93.3 ... 

The bonding and structure of the H2CO molecule are suggested by the three-dimensional sketch in Figure ll-18(c). A Lewis structure is given... 

Drawing three-dimensional sketches to show orbital overlaps, as in Figure 11-18(c), is not easy. A simpler, two-dimensional representation of the bonding scheme for formaldehyde is shown at the bottom of the previous page in Figure 11-19. Bonds between atoms are drawn as straight lines. They are labeled a or tt, and the orbitals that overlap are indicated. 

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