Concept Of Electronegativity Research Articles

Anisotropic properties of two-dimensional (2D) tin dihalide (SnX2, X = Cl, Br, I) monolayer binary materials

This paper investigated the electronic properties and photoresponse of two-dimensional SnX2 (X = Cl, Br, I) monolayer binary materials using computational techniques. The calculated band structure and density of states indicate that these are large band gap semiconducting materials with an indirect band gap. The studied chemical bonding mechanism shows the existence of the hybrid bonding of ionic and covalent bonds in these dihalide materials. The valence band (VB) and conduction band (CB) edge positions are also estimated, using the concept of electronegativity and band gap, to investigate the photocatalytic activity of SnX2. Next, we investigated the polarization and energy-dependent dielectric and optical functions along the crystallographic axes of these materials in the linear response approach of the perturbing incident oscillating light field. These materials exhibit an anisotropic behavior of these functions, especially in the high-energy visible and low-energy ultraviolet (UV) regions. The absorption of incident light photons is very fast in SnI2 than SnBr2 and SnCl2 in the low-energy UV region. It demonstrates the higher absorption coefficient and optical conductivity in Snl2. The obtained average static refractive index of SnCl2 is comparable to that of glass (1.5), showing its application as transparent material. The low reflection coefficient, less than 20%, makes them superior for antireflection coating materials in the infrared and visible regions. The prominent energy loss peaks show the existence of plasmon resonances in these materials. The most of losses occur in the UV region. The investigated electronic and photoresponse properties indicate that these Sn-based dihalide materials are excellent for electronic devices and optoelectronic applications. Also, the calculated VB and CB edge positions with respect to the normal hydrogen electrode show the favorable water-splitting capability of these materials.

Study of Conditional Glass Formers (II) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers refer as (II) of group V(A,B) and VI(A,B). They are Ta2O5, Nb2O5, V2O5, Cr2O3, Bi2O3, TeO2, MoO3, As2O3, WO3, Se2O3. It is observed that on decreasing the values of optical electronegativity, optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index, third order non linear optical susceptibility increases. All conditional glass forming oxides (II) are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For Conditional glass formers (II) radius ratio rc/ra = 0.250-0.492, [except Bi2O3 (0.75) & TeO2 (0.87)] and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which would result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

STUDY OF GLASS FORMERS ON BASICS OF OPTICAL ELECTRONEGATIVITY

Concept of electronegativity is used by so many researchers to study Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study so many glass systems. Here the concept of optical electronegativity is used to study these parameters in glass formers. It is observed that on decreasing the values of optical electronegativity; optical band energy, metallization criterion, and bond ionicity decreases; where as optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All glass forming oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory and rules for formation of glass and Sun’s single bond strength theory. For glass formers radius ratio rc/ra = 0.14-0.40, [except P2O5] and single bond strength greater than 90 Kcal/mol. Key Words: Band energy, Basicity, Optical dielectric constant, Oxide ion polarizability, Refractive index.

Study of Conditional Glass Formers (I) on Basics of Optical Electronegativity

Concept of Electronegativity is used by so many researchers to calculate Refractive index, Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-linear optical susceptibility to study the so many glass systems. Here the concept of optical electronegativity is used to study these parameters for conditional glass formers referred as (1) taken from group III (A,B) and IV (A,B); they are Y2O3, HfO2, ZrO2, Sc2O3, TiO2, Al2O3, In2O3, Ga2O3, and SnO2. It is observed that optical band energy, metallization criterion, and bond iconicity decreases; and optical dielectric constant, optical basicity, oxide ion polarizability refractive index and third order non linear optical susceptibility increases. All conditional glass formers (I) oxides are according to Pauling's packing rule, Goldschmidt radius ratio rule, Zachariasen's random network theory, rules for formation of glass and Sun’s single bond strength theory. For conditional glass formers (I) radius ratio rc/ra = 0.40-0.75 and single bond strength greater than 90 Kcal/mol. According to Sun’s, high bond strength oxides are not good glass formers because they themselves do not forms glass; but when they forms small ring in the melt of these materials which result in easy crystallization. Key Words: Refractive index Band energy, Dielectric constant, Metallization criterion, Basicity, Oxide ion polarizability, Bond ionicity, Third order non-liner optical susceptibility.

Energy Electronegativity and Chemical Bonding

Historical development of the concept of electronegativity (EN) and its significance and prospects for physical and structural chemistry are discussed. The current cutting-edge results are reviewed: new methods of determining the ENs of atoms in solid metals and of bond polarities and effective atomic charges in molecules and crystals. The ENs of nanosized elements are calculated for the first time, enabling us to understand their unusual reactivity, particularly the fixation of N2 by nanodiamond. Bond polarities in fluorides are also determined for the first time, taking into account the peculiarities of the fluorine atom's electronic structure and its electron affinity.

Electronegativity: A continuing enigma

AbstractThere continues to be confusion concerning the concept of electronegativity. Pauling's original approach, focusing upon an atom in a molecule, continues to be widely invoked. There has also been a more recent tendency to view electronegativity as the negative of the chemical potential and to extend it to molecules. However, this leads to results that are incompatible with chemical experience. A more effective approach, which gives results in overall agreement with Pauling's values, is to relate electronegativity to the average valence electron ionization energies of atoms.

Effect of selected organic additives on the properties of magnesia-chromite refractories

An attempt was made to adjust the kind of organic additives to the components of the mass for the magnesia-chromite products. This was done using Sanderson’s concept of electronegativity and molar electronegativity. Four organic additives were selected and their influence on the properties of the refractories was studied by performing a total factorial experiment 24. The basic properties of the refractories are presented in the form of seven response functions, six of which are described by statistically verified equations. The most favourable options were selected on the basis of six criteria that characterise the materials. The introduction of organic additives as slip agents into the mass, resulted in an improvement in practically all properties of the magnesia-chromite materials after firing. The purposefulness of the additive composition was demonstrated.

Electronegativity under Confinement.

The electronegativity concept was first formulated by Pauling in the first half of the 20th century to explain quantitatively the properties of chemical bonds between different types of atoms. Today, it is widely known that, in high-pressure regimes, the reactivity properties of atoms can change, and, thus, the bond patterns in molecules and solids are affected. In this work, we studied the effects of high pressure modeled by a confining potential on different definitions of electronegativity and, additionally, tested the accuracy of first-order perturbation theory in the context of density functional theory for confined atoms of the second row at the Hartree–Fock level. As expected, the electronegativity of atoms at high confinement is very different than that of their free counterparts since it depends on the electronic configuration of the atom, and, thus, its periodicity is modified at higher pressures.

From Electronegativity towards Reactivity-Searching for a Measure of Atomic Reactivity.

Pauling introduced the concept of electronegativity of an atom which has played an important role in understanding the polarity and ionic character of bonds between atoms. We set out to define a related concept of atomic reactivity in such a way that it can be quantified and used to predict the stability of covalent bonds in molecules. Guided by the early definition of electronegativity by Mulliken in terms of first ionization energies and Pauling in terms of bond energies, we propose corresponding definitions of atomic reactivity. The main goal of clearly distinguishing the inert gas atoms as nonreactive is fulfilled by three different proposed measures of atomic reactivity. The measure likely to be found most useful is based on the bond energies in atomic hydrides, which are related to atomic reactivities by a geometric average. The origin of the atomic reactivity is found in the symmetry of the atomic environment and related conservation laws which are also the origin of the shell structure of atoms and the periodic table. The reactive atoms are characterized by degenerate or nearly degenerate (several states of the same or nearly the same energy) ground states, while the inert atoms have nondegenerate ground states and no near-degeneracies. We show how to extend the use of the Aufbau model of atomic structure to qualitatively describe atomic reactivity in terms of ground state degeneracy. The symmetry and related conservation laws of atomic electron structures produce a strain (energy increase) in the structure, which we estimate by use of the Thomas-Fermi form of DFT implemented approximately with and without the symmetry and conservation constraints. This simplified and approximate analysis indicates that the total strain energy of an atom correlates strongly with the corresponding atomic reactivity measures but antibonding mechanisms prevent full conversion of strain relaxation to bonding.

The role of AlGaN/GaN heterostructure properties in barrier height variation of Au-free ohmic contacts

In this work, the temperature dependence of the specific contact resistance in Au-free ohmic contacts formed on AlGaN/GaN heterostructures is studied for different barrier layer characteristics, i.e. thickness and surface roughness of the AlGaN layer, and Al mole fraction. It is demonstrated that a minimum in specific contact resistance and Schottky barrier is reached with decreasing the AlGaN thickness to an optimum at which a maximum polarization field-induced carrier density ND-2DEG is formed. The Schottky barrier height at the metal/AlGaN interface is shown to be strongly linked to the heterostructure and interface properties. The dependence of the Schottky barrier height is found to be linear with Al mole fraction. The predictions from the physical interface induced gap states (IFIGS) and chemical electronegativity concepts are discussed.

A linear scaling law for predicting phase transition temperature via averaged effective electronegativity derived from A2M3O12-based compounds.

The chemical flexibility of A2M3O12-based compounds enables the design of materials with versatile functionalities such as ferroelastic switching, ion conduction and negative thermal expansion (NTE) above the ferroelastic transition temperature (Tt), which is promising for a variety of applications. Quantitative prediction of Tt is essential but lacking. Herein we propose a concept of averaged effective electronegativity (AEE) and establish a linear relationship between the Tt and AEE for A2M3O12-based compounds. The linear scaling law is validated using first principles calculations of the effective charge on oxygen and its effectiveness is verified experimentally by designing high entropy compounds Scx1Zrx2Hfx3Fex4Moy1Vy2O12 and a NTE compound Zr2MoVPO12 with expected Tt. Generalization of the linear scaling law to other NTE oxides with displacive phase transition is also demonstrated. The findings can be used as a simple and effective approach to guide the design of novel compounds with desired properties and Tt.

METAVALENT CHEMICAL COMPOUNDS OF THE TYPE AIBVCVI2 (AI – Li, Na, K, Rb, Cs; BV – As, Sb, Bi; CVI – Se, Te)

The concept of chemical bonding is one of the key concepts in the modern chemical science. The main types of chemical bonds traditionally distinguished in the scientific literature are ionic, covalent and metallic; whereas hydrogen bonds and intermolecular interaction forces are usually taken as secondary bonds. It should be noted, however, that there are no sharp boundaries for the above types of chemical bonds.In order to predict the type of chemical bond between atomic particles, a special atomic property called the electronegativity [i.e. the ability of a given atom in a molecule to attract electron density (or valent electrons)] is widely used. The concept of electronegativity and the first scale of electronegativities of chemical elements were proposed by L. Pauling in 1932; later, several alternative scales of electronegativities were developed, including those by Mulliken and by Allred–Rochow.Using the difference between the electronegativities of atoms (DEN) and the sum of the electronegativities of atoms (SEN), one can obtain quantitative parameters which characterize the chemical bonds in specific compounds. In particular, the difference in the electronegativities of the A and B atoms characterizes the degree of ionicity for the A–B bond, while the sum of electronegativities indicates either the degree of covalency (at relatively large SEN values) or the degree of metallicity (at low SEN values). The sum of electronegativities can be replaced, if necessary, by the average electronegativity (ENav.) of the compound. Taking the elementary substances Cs and F2 and the binary compound CsF as reference points in the coordinates ENav.–DEN, a diagram triangle was constructed, which conveniently and clearly illustrates the type of chemical bond of different chemical compounds.The analysis of the ternary chalcogenide AIBVCVI2 (AI – Li, Na, K, Rb, Cs; BV – As, Sb, Bi; CVI – Se, Te) compounds (which have been studied for a long time by the researchers of the Uzhhorod National University) by using the aforementioned diagram triangle in the coordinates ENav.–DEN has revealed the fact that the considered compounds are characterized by the combined (so-called "metavalent") chemical bonding recently identified in the specialized scientific literature as a separate bonding type.

Opportunities to use interactive tasks in chemistry within the Middle Years Programme (basic school) of the International Baccalaureate

Problem and purpose. Information and communication technologies (ICT) are considered one of the most progressive and effective means of increasing interest in learning, as well as developing students in modern teaching methods. In Russia, the use of ICT and the development of its theoretical aspects in teaching chemistry under the Middle Years Programme (MYP, basic school) of the International Baccalaureate is at an embryonic level and, therefore, is a modern and very urgent problem of the education system within the framework of the International Baccalaureate. New methods and means based on the use of ICT in the educational process contribute to the growing interest in the study of chemistry. Increasing the level of independence in educational activities within the framework of working with ICT contributes to the formation of a competent, developed personality, teaches children to make adequate decisions, and motivates to improve self-preparation for lessons. Thanks to the continuous movement of modern education towards change and progress, there are more and more new developments and teaching aids that can be used in teaching chemistry. All this contributes to the creation and maintenance of a stable interest in educational processes, both in the independent search and solution of problems, and at school in the classroom. Often, the generally accepted approaches to the study of the topic of valence, existing today, do not give the desired and desired results. And the insufficient assimilation of this topic by students leads to a deterioration in academic performance in the further paragraphs of the chemistry course of the basic school curriculum. In the MYP (basic school), the study of the topic Valence is replaced by an explanation of the concepts of electronegativity and oxidation state, which leads to the loss of one of the fundamental concepts in chemistry. That fact defines the problem of the article. The purpose of the article is to describe approaches to increasing the interest and attention of students in the context of the use of innovative interactive technologies. Methodology. The methodological basis was the scientific and methodological works of A.K. Akhlebinin, N.P. Bezrukova, G. Vern, L.S. Vygotsky, P.Ya. Galperin, S.A. Gerus, A.A. Zhurin, V.V. Zagorsky, L. S. Zaznobina, O.S. Zaitsev, M.V. Zueva, R.G. Ivanova, N.E. Kuznetsova, G.Ya. Lastushkina, T.S. Nazarova, E.I. Mashbitsa, E.S. Polat, L.F. Pleukhova, I.V. Robert, T.A. Sergeeva, N.F. Talyzina, S.G. Chaikova, G.M. Chernobelskaya, L.L. Chunikhina, M. Shanon. Results. The expediency of using interactive tasks in chemistry (on the example of the topic Valence) in teaching schoolchildren under the MYP has been substantiated by increasing the general level of academic performance on this topic, as well as interest in chemistry lessons. Approaches to the selection of content (on the example of the topic Valence) for the creation of interactive tasks, including scientific, systematic, age-appropriate, are determined. A system of interactive tasks for studying the topic Valence under the MYP was developed and tested, which contains teaching materials for preparing students on the specified topic, including the theoretical part and analysis of examples. Conclusion. The results allowed to conclude that the creation and use of a specially prepared system of interactive tasks in chemistry (using the example of the Valence topic) for the MYP leads to a significant simplification of the study of this topic and an increase in the level of intrinsic motivation to study chemistry.

Commentary on the Models of Electronegativity

The concept of electronegativity is one of the most relevant concepts in the chemical sciences from the second half of the past century. It is used to understand the polarity of bonds, bond dipole ...

Selection of contact materials to p-type halide perovskite by electronegativity matching

The performance of perovskite optoelectronic devices depends critically on the contact between the active layer and charge transport materials. To reveal the mechanism of barrier formation on perovskite surfaces, we studied Schottky junctions between various metals and a p-type perovskite CsSnBr3. By constructing slab models of the junction interface and aligning atomic core levels, the contacts between Au/CsSnBr3 and graphite/CsSnBr3 were found to be ohmic, but various other metals produced Schottky junctions with CsSnBr3. These calculation results, supported by x-ray photoelectron spectroscopy measurements, suggest that the barrier height of a metal/CsSnBr3 junction is a linear function of the metal’s electronegativity, rather than its work function. By introducing the concept of effective electronegativity for compounds, this trend was extended to a general rule that a suitable transport material should have an effective electronegativity to match that of the perovskite.

Relationship between the Atomic Structure and Electrochemistry. 1. Electric Force, Standard Reduction Potential E°, and Standard Reaction Gibbs Free Energy ΔG°.

The relationship among the standard reaction Gibbs free energy ΔG°, the standard reduction potential E°, and the atomic structure parameters of radius, nuclear charge, and isoelectronic orbitals nl is accomplished through the attraction electric force Felec. In relationship with E°, it was necessary to define two new reference scales: E0° with a final state of E° in the element, which allowed to have a parabolic trend of ΔG° versus Felec, and E°,0 whose final state is the ion with a more negative charge (e.g., −1, –2, −3). The relationship with ΔG° is related to the concept of chemical stability, and the relationship with E°,0 is more related to the concept of electronegativity. In relationship with ΔG°, it was necessary to predict the values of possible new cations and noncommon cations in order to find a better trend of ΔG° versus Felec, whose stability is analyzed by Frost diagrams of the isoelectronic series. This dependence of ΔG° on Felec is split into two terms. The first term indicates the behavior of the minimum of ΔG° for each isoelectronic orbital nl, while the second term deals with the parabolic trend of this orbital. For the minima of the configuration np6, a hysteresis behavior of the minima of ΔG° is found: an exponential behavior from periods 1 and 2 and a sigmoidal behavior from periods 5 and 4 to interpolate period 3. It is also found that the proximity of unfilled np or (n + 1)s orbitals induces instability of the ion in configurations ns2/nd2/4f2 and nd10/nd8(n + 1)s2, respectively. On the contrary, the stability of the orbitals np6 does not depend on the neighboring empty (n + 1)s0 orbitals. Both phenomena can be explained by the stability of the configuration of noble gas np6 and the nd10(n + 1)s2 configuration. We have also found that it is possible to increase the reduction potential E°,0 (macroscopic electronegativity), although the electric force Felec decreases because the orbital overlap influences the electronegativity.

Electronegativities of Pauling and Mulliken in Density Functional Theory.

Electronegativity is a fundamental concept in chemistry that allows one to infer important aspects about the interactions between chemical species. In the present work we make use of the framework provided by the density functional theory of chemical reactivity, to discuss in a unified way the approaches to the concept of electronegativity developed by Pauling and by Mulliken. Our analysis starts by making use of the identification of the electronegativity of Mulliken with the chemical potential of density functional theory, and continues to show that the ionic correction proposed by Pauling can be derived, with certain approximations, from the quadratic smooth interpolation of the energy as a function of the number of electrons in terms of the chemical potentials and the hardnesses of the interacting species, from which one can infer the close qualitative relationship between Pauling's electronegativity and the electrophilicity concept.

DEFECT FORMATION MECHANISMS OF ZINC SELENIDE LAYERS DOPED BY ISOVALENT IMPURITIES OF THE II GROUP

The paper discusses the mechanisms of defect formation in melt zinc selenide crystals doped with isovalent impurities of the second group of the Periodic Table. An analytical calculation of the concentrations of equilibrium point defects was carried out by the method of quasichemical reactions using the concepts of electronegativity and effective charge. It has been established that the dominant defects in the doped material are singly charged vacancies of zinc V'Zn and selenium V·Se, as well as singly charged interstitial selenium Se'i. It is shown that the increase in doping temperature Ta from 373 to 1237 K causes se increase of acceptor centers number (V'Zn and Se'i) and decrease of concentration of donor ounces V·Se however, the conductivity of doped substrates at 300 K remains a hole in the whole range of change Ta. At Ta = 373 K the estimated concentration of free holes is ~1019 cm-3 and satisfactorily consistent with the value p determined from the temperature dependence of the layer resistance ZnSe:Ca.

Robert G. Parr (1921-2017).

Robert G. Parr, emeritus professor at the University of North Carolina at Chapel Hill, passed away at the age of 95 on March 27, 2017. Parr was one of the founders of quantum chemistry, and his seminal contributions to the field included ab initio methods, semiempirical techniques, molecular spectroscopy, and density functional theory. Bob's influence perfuses quantum chemistry, including both semiempirical (a strategy he pioneered) and ab initio (a term he coined) approaches. Indeed, his work is so pervasive that it is easier to characterize his research style—mathematical elegance; deep intuition; minimalist writing; curiosity; prescience—than his research discoveries. He approached chemistry with the humility of one who recognizes that the discipline is so big that it can not be completely mastered, even by its most accomplished practitioners, and with the grace of one who regards advancing science as an intrinsically ennobling pursuit. Bob's scientific journey started as a molecular spectroscopist—guided by Paul Cross at Brown University (BS) and Bryce Crawford at the University of Minnesota (PhD)—working to compute molecular vibrational frequencies. This led to pioneering work on configuration interaction calculations in the early 1950s. He continued to work on ab initio methods during this decade (including seminal work on strong orthogonality and electron group functions), but this is also when he laid the foundations of semiempirical quantum chemistry. He established the zero-differential overlap approximation and showed how to rigorously derive π-electron effective Hamiltonians for conjugated hydrocarbons. The need to parameterize the integrals in semiempirical methods led to the Pariser–Parr–Pople model (1953), which was the first method to successfully predict the electronic spectra of sizable organic molecules. The Pariser–Parr–Pople Hamiltonian is still used today, most often in the simplified form that Hubbard introduced almost a decade later. Topics related to molecular spectroscopy continued to dominate Bob's work in the 1960s and early 1970s. During this period, he developed generalized Hellmann–Feynman theorems and the Simons–Parr–Finlan coordinate transformation. Nonetheless, more traditional quantum chemistry research (including the corresponding orbital transformation, the analysis of basis-set convergence, and the study of wavefunction asymptotics) continued apace. In the late 1970s, his interests shifted to (reduced) density matrices and density functional theory (DFT). These topics, alongside periodic forays into information theory, spectroscopy, wavefunction methods, and other topics, would dominate the last four decades of his life. More than anyone else, he brought DFT to fruition as a method for chemists for quantitative prediction and qualitative understanding of chemistry. He made key contributions to the mathematical framework of DFT, including the elucidation of the derivative discontinuity, the characterization of the exchange-correlation potential, and the development of functional-analytic techniques. He created computational methods, including the pervasive Lee–Yang–Parr correlation energy functional. He pioneered the idea that chemical concepts could, and should, be given precise mathematical definitions, and with Ralph Pearson he used the DFT framework to define chemical hardness and to clarify the hard/soft acid/base principle. He also used DFT to provide modern refinements to the concepts of electronegativity and frontier-molecular-orbital theory. Bob was beyond generous, both scientifically and personally. He would not agree to be a co-author unless he felt he had made an essential and specific intellectual contribution to a paper. Nearly half the papers describing research performed in his laboratory did not include his name, including classic papers on the Hartree–Fock molecular orbitals, the contracted Schrödinger equation, local thermodynamics, classical DFT, and electronegativity-equalization methods. Over the course of his professional career, he was Professor of Chemistry at Carnegie Institute of Technology (now Carnegie Mellon University; from 1948), Johns Hopkins University (from 1962), and the University of North Carolina at Chapel Hill (from 1974). He won numerous fellowships and awards, and was a member of the US National Academy of Sciences. Bob pursued science in an idyllic and romantic way, and it comes as no surprise that he also wrote poems. The late Vedene Smith liked to refer to the extended circle of Parr's students, postdoctoral fellows, senior visitors, and their associates as the Parr-tisans. He was not the only person to note that people who came through Bob's group had a certain je ne sais quoi. It was impossible to work with Bob and not be inspired by his irrepressible curiosity, his eagerness to try new mathematical tools and new intuitive strategies, his obsession with all things that were interesting and fundamental, and, most of all, his example as a scientific global citizen.

Charge-Shift Corrected Electronegativities and the Effect of Bond Polarity and Substituents on Covalent-Ionic Resonance Energy.

Bond dissociation energies and resonance energies for HnA-BHm molecules (A, B = H, C, N, O, F, Cl, Li, and Na) have been determined in order to re-evaluate the concept of electronegativity in the context of modern valence bond theory. Following Pauling's original scheme and using the rigorous definition of the covalent-ionic resonance energy provided by the breathing orbital valence bond method, we have derived a charge-shift corrected electronegativity scale for H, C, N, O, F, Cl, Li, and Na. Atomic charge shift character is defined using a similar approach resulting in values of 0.42, 1.06, 1.43, 1.62, 1.64, 1.44, 0.46, and 0.34 for H, C, N, O, F, Cl, Li, and Na, respectively. The charge-shift corrected electronegativity values presented herein follow the same general trends as Pauling's original values with the exception of Li having a smaller value than Na (1.57 and 1.91 for Li and Na respectively). The resonance energy is then broken down into components derived from the atomic charge shift character and polarization effects. It is then shown that most of the resonance energy in the charge-shift bonds H-F, H3C-F, and Li-CH3 and borderline charge-shift H-OH is associated with polarity rather than the intrinsic atomic charge-shift character of the bonding species. This suggests a rebranding of these bonds as "polar charge-shift" rather than simply "charge-shift". Lastly, using a similar breakdown method, it is shown that the small effect the substituents -CH3, -NH2, -OH, and -F have on the resonance energy (<10%) is mostly due to changes in the charge-shift character of the bonding atom.