COVALENT BONDS RESULT FROM A SHARING OF ELECTRONS

I magine two children playing together and sharing their toys. A force that 

The effect of the positive nuclear charge (represented by red shading) of a fluorine atom extends beyond the atom s outermost occupied shell. This positive charge can cause the fluorine atom to become attracted to the unpaired valence electron of a neighboring fluorine atom. Then the two atoms are held together in a fluorine molecule by the attraction they both have for the two shared electrons. Each fluorine atom achieves a filled valence shell. 

When writing electron-dot structures for covalent compounds, chemists often use a straight line to represent the two electrons involved in a covalent bond. In some representations, the nonbonding electron pairs are left out. This is done in instances where these electrons play no significant role in the process being illustrated. Here are two frequently used ways of showing the electron-dot structure for a fluorine molecule without using spheres to represent the atoms  

Remember—the straight line in both versions represents two electrons, one from each atom. Thus we now have two types of electron pairs to keep track of. The term nonbondingpair refers to any pair that exists in the electron-dot structure of an individual atom, and the term bonding pair refers to any pair that results from formation of a covalent bond. In a nonbonding pair, both electrons come from the same atom in a bonding pair, one electron comes from one of the 

Molecules are the fundamental units of the gaseous covalent compound fluorine, F2. Notice that in this model of a fluorine molecule, the spheres overlap, whereas the spheres shown earlier for ionic compounds do not. Now you know that this difference in representation is because of the difference in bond types. 

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Covalent Bonds Result from a Sharing of Electrons... 

COVALENT BONDS RESULT FROM A SHARING OF ELECTRONS... 

Covalent bonds result from the sharing of electrons between atoms. In this case, instead of giving up or acquiring electrons, an atom can obtain a filled valence shell by sharing electrons. For example, two chlorine atoms can achieve a filled valence shell of 18 electrons by sharing their unpaired valence electrons. 

A covalent bond results from the sharing of electrons between two atoms. The most familiar examples of covalent bonding are seen in tire interactions of nonmetallic elements with one another. We devote much of tiiis chapter and tire next to describing and understanding covalent bonds. 

As shown in Figure 7.1, the electrons are now attracted to both nuclei. That means the electron on atom 1 can zip over and bask in the positive glow of the nucleus on atom 2. The same is true for the electron on atom 2. A covalent bond results from this sharing of the negatively charged electrons between the two positively charged nuclei. In addition, the presence of electrons (really electron density) between the two nuclei will shield the nuclei from each other, thereby... 

A covalent bond arises from the sharing of electrons between atoms. This results in an increase in electron density between the two atoms. Thus, covalent bonds are represented as the overlap of atomic orbitals. The overlap between two atomic orbitals, i2, on atoms 1 and 2 is represented in terms of the overlap integral, S, which is defined as... 

Double bond A covalent bond resulting from the sharing of four electrons (two pairs) between two atoms. 

Covalent Covalent bonding stems from the sharing of electrons and the overlap and sharing of electrons orbitals between atoms. Covalent bonds are very strong as a result of this. Covalent bonds have directionality, or a preference for a specific orientation relative to one another, this results in molecules of interesting and specific shapes. As a result, elaborate molecules can be made that have specific structures and symmetry, which we describe in Chapter 7. 

SECTION 8.3 A covalent bond results from the diaring of electrons. We can represent the electron distribution in molecules by means of Lewis structures, which indicate how many talence electrons are involved in forming bonds and how many remain as unshared electron pairs. The octet rule helps determine how many bonds will be formed between two atoms. The sharing of one pair of electrons produces a single bond the sharing of two or three pairs of electrons between two atoms produces double or triple bonds, respectively. Double and triple... 

A single covalent bond results from the sharing of one pair of electrons between bonded atoms. It is represented by a single dash sign (—). A skeletal structure is an arrangement of atoms in a Lewis structure to correspond to the actual arrangement found by exp>eriment. 

In contrast to a covalent bond, an ionic bond results not from a sharing of electrons but from a transfer of one or more electrons from one atom to another. As noted previously, ionic bonds generally form between a metal and a nonmetal. Metallic elements, such as sodium, magnesium, and zinc, tend to give up electrons, whereas nonmetallic elements, such as oxygen, nitrogen, and chlorine, tend to accept electrons. 

Covalent bond (Section 1.2) A bond that results from the sharing of electrons between two nuclei. A covalent bond is a two-electron bond. 

In general a covalent bond between two atoms, for example X and Y, results from a process of electron sharing. One electron is furnished by X, the other by Y, and the two interact to form a covalent bond... 

The electrons shared in a covalent bond result from an overlap of atomic orbitals to give a new molecular orbital. Electrons in the Is- and 2s-orbitals combine to give sigma (o-) bonds. 

In chapter 1 we mentioned early theories of bonding, and when we considered the formation of a molecule of chlorine from two chlorine atoms, we drew structures for both chlorine atoms to show the outer electronic configurations. We then considered the covalent bond to result from a sharing of two electrqni re... 

Molecular orbital (MO) theory combines the tendency of atoms to fill their octets by sharing electrons (the Lewis model) with their wavelike properties—assigning electrons to a volume of space called an orbital. According to MO theory, covalent bonds result from the combination of atomic orbitals to form molecular orbitals— orbitals that belong to the whole molecule rather than to a single atom. Like an atomic orbital that describes the volume of space around the nucleus of an atom where an electron is likely to be found, a molecular orbital describes the volume of space around a molecule where an electron is likely to be found. Like atomic orbitals, molecular orbitals have specific sizes, shapes, and energies. 

INTRODUCTION AND SECTION 8.1 In this chapter we have focused on the interactions that lead to the formation of chemical bonds. We classify these bonds into three broad groups ionic bonds, which result from the electrostatic forces that exist between ions of opposite charge covalent bonds, which result from the sharing of electrons by two atoms and metallic bonds, which result fiom a delocalized sharing of electrons in metals. The formation of bonds involves interactions of the outermost electrons of atoms, their valence electrons. The valence electrons of an atom can be represented by electron-dot symbols, called Lewis symbolSL The tendencies of atoms to gain, lose, or share their valence electrons often follow the octet ruie, which can be viewed as an attempt by atoms to achieve a noble-gas electron configuration. 

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