Electronegativity The tendency of an atom

The potential measured with an electrode in contact with a solution of its ions. Electrode potential values will predict whether a substance will be reduced or oxidized. Values are usually expressed as a reduction potential (M + —> M). A positive electrode potential would indicate that reduction is spontaneous. A negative potential for this reaction would suggest that the oxidation reaction (M —> M +) would be spontaneous. Electronegativity The tendency of an atom to pull an electron toward it in a chemical bond ... 

Electronegativity the tendency of an atom in a molecule to attract shared electrons to itself. (13.2)... 

Another fundamental property of chemical bonds is polarity. In general, it is to be expected that the distribution of the pair of electrons in a covalent bond will favor one of the two atoms. The tendency of an atom to attract electrons is called electronegativity. There are a number of different approaches to assigning electronegativity, and most are numerically scaled to a definition originally proposed by Pauling. Part A of Table 1.6... 

As has just been described, when a covalent bond forms between two atoms, there is no reason to assume that the pair of electrons is shared equally between the atoms. What is needed is some sort of way to provide a relative index of the ability of an atom to attract electrons. Linus Pauling developed an approach to this problem by describing a property now known as the electronegativity of an atom. This property gives a measure of the tendency of an atom in a molecule to attract electrons. Pauling devised a way to give numerical values to describe this property that makes use of the fact that the covalent bonds between atoms of different electronegativity are more stable than if they were purely... 

Electronegativity is defined as the tendency of an atom to attract electrons to itself in a chemical bond. 

Electronegativity (x) is an empirical measure of the tendency of an atom in a molecule to attract electrons. The noble gases, therefore, do not have electronegativity values because they do not easily form molecules. The electronegativity value depends primarily on the element, but also on the oxidation state, i.e., the electronegativity of elements with variable valency can be different for each valency thus that of Fe2+ is different from that of... 

Electronegativity is the tendency of an atom to attract the bonding electrons within a compound to itself. It depends upon the nuclear charge (proton number) and the atomic radius of the atom. It is these factors that control the ionization energy of the atom which in turn is related to the ability of an atom to attract electrons. 

The earlier sections on ionic bonding and covalent bonding refer to the concept of electronegativity, or the tendency of an atom to draw electrons toward itself. Ionic bonds form between atoms with large differences in electronegativity, whereas covalent bonds form between atoms with smaller differences in electronegativity. In truth, there s no natural distinction between the two types of bonds (ionic and covalent) they lie on opposite sides of a spectrum of polarity, or unevenness in the distribution of electrons within a bond. 

Pople argued that this would better account for the tendency of an atomic orbital to both lose and gain electrons and hence "would better represent the departure of an atom from neutrality in a molecular environment . The value of the orbital electronegativity i (I+A) is determined, as described above, from appropriate spectroscopic data. 

Electronegativity is a periodic feature of the elements that is almost the exact opposite of ionization energy. Ionization energy is a measure of how hard it is to remove an electron from an atom, while electronegativity is a measure of the tendency of an atom to attract electrons. The two numbers are arrived at differently, however. Ionization energy is a property of a stand-alone atom in the gaseous state. Electronegativity is a property of an atom when it is joined to another atom in a chemical bond. 

Relating Eg to electronegativity provides a theoretical basis of this concept. Here is a definition without assumptions and derived directly from first principles. It is a function of the electronic configuration of atoms only and emerges naturally as the response of an atom to its environment. It is indeed the tendency of an atom to interact with electrons [117] and the fundamental parameter that quantifies chemical affinity and bond polarity. 

Electron affinity is a measure of the tendency of an atom to accept an electron. Excluding noble gases, electron affinity increases as the atomic number increases within a given period and decreases with an increase in atomic number within a group. The scale of electronegativities allows a chemist to evaluate the electron affinity of specific atoms when they are incorporated into a compound. Recall from Chapter 6 that electronegativity indicates the relative ability of an atom to attract electrons in a chemical bond. 

The essential points of this section can be summarized as follows The tendency of an atom to donate or accept electrons in a chemical bond is expressed by its electronegativity. Highly electronegative atoms, on the right side of the periodic table, readily accept electrons to form negative ions. Highly electropositive atoms, on the left side of the table, readily donate electrons to form positive ions. Bonds formed by the complete transfer of an electron from one atom to another to form a pair of ions bound largely by electrostatic attraction are called ionic (see discussion in Section 3.5). 

Covalent bonds may be either polar or nonpolar. In a nonpolar bond such as that in the hydrogen molecule, H2, (H H or H—H) the electron pair is shared equally between the two hydrogen nuclei. We defined electronegativity as the tendency of an atom to attract electrons to itself in a chemical bond (see Section 6-6). Both H atoms have the same electronegativity. This means that the shared electrons are equally attracted to both hydrogen nuclei and therefore spend equal amounts of time near each nucleus. In this nonpolar covalent bond, the electron density is s)mimetrical about a plane that is perpendicular to a line between the two nuclei. This is true for all homonuclear diatomic molecules, such as H2, O2, N2, F2, and CI2, because the two identical atoms have identical electronegativities. We can generalize ... 

Electronegativity is the tendency of an atom to attract electrons in a molecule. Large differences in electronegativity between atoms in a given molecule often cause the complete transfer of an electron from the unfilled outer... 

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