Carbon atom, covalent bond with

Organic compounds Substances whose molecules contain one or more carbon atoms covalently bonded with another element (including hydrogen, nitrogen, oxygen, the halogens as well as phosphorus, silicon and sulfur). 

Because each carbon forms covalent bonds with two atoms, only two orbitals (an s and ap) are hybridized. Two degenerate sp orbitals result. Each carbon atom in ethyne, therefore, has two sp orbitals and two unhybridizedp orbitals (Figure 1.17). 

The hundreds of thousands of organic molecules have various chemical and physical properties and three-dimensional structures. However, certain similarities exist. Organic compounds, of course, are covalently bonded, carbon based molecules. The ability of carbon atoms to bond with one another allows the formation of long chains, double and triple bonds, and even rings. 

The carbon atoms are bonded with covalence among each other through three kinds of hybrid orbits (sp, sp, sp ) in activated carbon molecules. The activated carbons have complex structures because the ratios of hybrid orbits are different in different samples. The unit structure for mediation of hybrid carbon may distribute randomly and the structure and amount are determined by the raw material, manufacture technique and conditions. Thus, the steric configuration of activated carbon is amorphous constructed by the short-range order three-dimensional structures, each of which results from the more or less randomly-arranged hybrid carbon atoms. Thereinto carbon atoms are mainly sp and sp hybrids. ... 

When carbon forms four covalent bonds with halogen atoms the second quantum level on the carbon is completely filled with electrons. Most of the reactions of the Group IV tetrahalides require initial donation by a Lewis base (p. 91) (e.g. water, ammonia) which attaches initially to the tetrahalide by donation of its electron pair. Hence, although the calculated free energy of a reaction may indicate that the reaction is energetically favourable, the reaction may still not proceed. Thus we find that the tetrahalides of carbon... 

The carbon atom m bromomethane can accept an electron pair if its covalent bond with bromine breaks with both electrons m that bond becoming an unshared pair of bromide ion Thus bromomethane acts as a Lewis acid m this reaction... 

Here is a situation we haven t met before. After using the two available partially filled orbitals to form covalent bonds with hydrogen atoms, there remains a vacant valence orbital. In the electron dot formulation (36) we see that the carbon atom finds itself near only six electrons in CH2. The valence orbitals will accommodate eight electrons. Because one valence or-... 

Using the carbon atom covalent radius 0.77 A and the covalent radii given in Figure 19-3, predict the C—X bond length in each of the following molecules CF<, CBr4, CI4. Compare your calculated bond lengths with the experimental values C—F in CF4 = 1.32 A, C—Br in CBr = 1.94 A, C—I in CI4 = 2.15 A. 

Carbon monoxide is a colorless, odorless, flammable, almost insoluble, very toxic gas that condenses to a colorless liquid at — 90°C. It is not very reactive, largely because its bond enthalpy (1074 kj-mol-1) is higher than that of any other molecule. However, it is a Lewis base, and the lone pair on the carbon atom forms covalent bonds with J-block atoms and ions. Carbon monoxide is also a Lewis acid, because its empty antibonding Tr-orbitals can accept electron density from a... 

Carbon likes to form bonds so well with itself that it can form multiple bonds to satisfy its valence of four. When two carbon atoms are linked with a single bond and their other valencies (three each) are satisfied by hydrogens, the compound is ethane. When two carbons are linked by a double bond (two covalent bonds) and their other valencies (two each) are satisfied by hydrogens, the compound is ethylene. When two carbons are linked by a triple bond (three covalent bonds) and their other valencies (one each) are satisfied by hydrogens, the compound is acetylene. 

This Lewis structure shows methane, the simplest organic compound. The carbon atom has four valence electrons, and it obtains four more electrons by forming four covalent bonds with the four hydrogen atoms. 

Fig. 4.18 The different degree to which electrons move collectively in various forms of carbon material as evidenced by distinct intensity of the plasmon peak located about 6 eV in EELS spectra (arrow). Hydrogen atoms can make less strong covalent bonds with participation of n electrons if the interplanar distance is increased in layered graphitic nanocrystals as seen in carbon nanosheUs (frame in Fig. 4.17) and in disordered graphitic carbons (Sect. 4.3.1). After [60]...

Carbon-12 is the basis for the average atomic mass units (amu) that is used to determine the atomic weights of the elements. Carbon is one of the few elements that can form covalent bonds with itself as well as with many metals and nonmetals. 

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