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Network solids carbon

Fig. 17-2. Carbon forms network solids diamond and graphite. Fig. 17-2. Carbon forms network solids diamond and graphite.
Silica, Si02, is a hard, rigid network solid that is insoluble in water. It occurs naturally as quartz and as sand, which consists of small fragments of quartz, usually colored golden brown by iron oxide impurities. Some precious and semiprecious stones are impure silica (Fig. 14.36). Flint is silica colored black by carbon impurities. [Pg.732]

The most typical example of a network solid is diamond. In diamond each carbon atom is covalently bonded to four other carbon atoms forming a tetrahedral shape. (The type of hybridization that corresponds to this tetrahedral structure is sp3) This structure is extremely strong and this makes diamond the hardest natural substance. [Pg.53]

B—Diamond is a covalent network solid with a large number of strong covalent bonds between the carbon atoms. [Pg.176]

This improvement made it possible to resolve micron distances behind the front. The value of the peak conductivity was found to correlate so strongly with the amount of solid carbon present in the detonation products, as to suggest that the principal path of electrical conduction in that region is thru a con-tinous network of solid carbon... [Pg.262]

Carbon exists in more than 40 known structural forms, or allotropes, several of which are crystalline but most of which are amorphous. Graphite, the most common allotrope of carbon and the most stable under normal conditions, is a crystalline covalent network solid that consists of two-dimensional sheets of fused six-membered rings (Figure 10.26a). Each carbon atom is sp2-hybridized and is connected to three other carbons. The diamond form of elemental carbon is a covalent network solid in which each carbon atom is sp3-hybridized and is bonded with tetrahedral geometry to four other carbons (Figure 10.26b). [Pg.411]

Organic substances such as methane, naphthalene, and sucrose, and inorganic substances such as iodine, sulfur trioxide, carbon dioxide, and ice are molecular solids. Salts such as sodium chloride, potassium nitrate, and magnesium sulfate have ionic bonding structures. All metal elements, such as copper, silver, and iron, have metallic bonds. Examples of covalent network solids are diamond, graphite, and silicon dioxide. [Pg.198]

C) While both forms of carbon are network solids, the structure of graphite is large sheets of molecules that easily slide past one another. In diamonds, however, the carbon atoms bond both vertically and horizontally, allowing for much more rigid three-dimensional structures, some of the hardest known. [Pg.195]

In every example seen so far the covalent bonds have held atoms together in order to make molecules. However, there exist substances such as diamond and graphite where the carbon atoms are covalently bonded but do not bond to form molecules. Such cases are called network solids the atoms bond to each other in a continuous network. The large network gives these solids a very high melting point. Also note that because both diamond and graphite are made up of the same element and are different substances, they are labeled allotropes of each other. [Pg.90]

Many atomic solids contain strong directional covalent bonds. We will call these substances network solids. In contrast to metals, these materials are typically brittle and do not efficiently conduct heat or electricity. To illustrate network solids, in this section we will discuss two very important elements, carbon and silicon, and some of their compounds. [Pg.785]

Carbon occurs in the allotropes (different forms) diamond, graphite, and the fullerenes. The fullerenes are molecular solids (see Section 16.6), but diamond and graphite are typically network solids. In diamond, the hardest naturally occurring substance, each carbon atom is surrounded by a tetrahedral arrangement of other carbon atoms, as shown in Fig. 16.26(a). This structure is stabilized by covalent bonds, which, in terms of the localized electron model, are formed by the overlap of sp3 hybridized atomic orbitals on each carbon atom. [Pg.785]

Diamond is a network of carbon atoms, each carbon entity bonded to the next through a covalent bond in a tetrahedron arrangement, as shown in figure 1.12.3. Diamond s sibling, solid graphite, is also made of pure carbon, but in graphite the carbons are bonded in sheets that can slide over... [Pg.182]

A number of solids are composed only of atoms interconnected by a network of covalent bonds. These solids are often called covalent network solids. Quartz is a network solid, as is diamond. See Figure 9-20. In contrast to molecular solids, network solids are typically brittle, nonconductors of heat or electricity, and extremely hard. In a diamond, four other carbon atoms surround each carbon atom. This tetrahedral arrangement forms a strongly bonded crystal system that is extremely hard and has a very high melting point. [Pg.267]

In diamond, each carbon atom is bonded to four other carbon atoms. Network solids, such as diamond, are often used in cutting tools because of their hardness. [Pg.267]

Covalent network solids Atoms such as carbon and silicon, which can form multiple covalent bonds, are able to form covalent network solids. In Chapter 7, you learned how the structures of graphite and diamond give those solid allotropes of carbon different properties. Figure 13-20 shows the covalent network structure of quartz. Based on its structure, will quartz have properties similar to diamond or graphite ... [Pg.402]

Network solids formed from one element only, such as the allotropes graphite and diamond in which the carbon atoms are connected differently Allotropes are forms of an element with different solid structures. [Pg.51]

Covalent solids (or network solids ) can be considered giant molecules that consist of covalently bonded atoms in an extended, rigid crystalline network. Diamond (one crystalline form of carbon) and quartz are examples of covalent solids (Figure 13-32). Because of their rigid, strongly bonded structures, mst covalent solids are very hard and melt at high temperatures. Because electrons are localized in covalent bonds, they are not freely... [Pg.526]

The type of attractive forces within solids depends on the identity of the unit particle and the chemical bonds it can form. The forces between atoms in a covalent network solid (such as carbon in diamond) are covalent bonds. These bonds result when at least one pair of electrons is shared by two atoms. The forces between atoms within metallic elements (such as iron) are metallic bonds. Electrostatic attractions—also called ionic bonds—are the forces between ions, atoms which have lost one or more electrons to become positively charged ions or which have gained one or more electrons to become negatively charged ions (such as those found in NaCI). Ionic compounds are often known as salts. Covalent, metallic, and ionic bonds are strong chemical bonds. [Pg.78]

So far we have considered solids in which atoms occupy the lattice positions. In some of these substances (network solids), the solid can be considered to be one giant molecule. In addition, there are many types of solids that contain discrete molecular units at each lattice position. A common example is ice, where the lattice positions are occupied by water molecules [see Fig. 10.12(c)]. Other examples are dry ice (solid carbon dioxide), some forms of sulfur that contain Ss molecules [Fig. 10.34(a)], and certain forms of phosphorus that contain P4 molecules [Fig. 10.34(b)]. These substances are characterized by strong... [Pg.466]


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See also in sourсe #XX -- [ Pg.799 , Pg.800 ]




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