The presence of pesticide residues in children's diets is a significant public health concern. This comprehensive review examines the prevalence of pesticide residues in children's diets, the potential health risks associated with exposure to these chemicals, and the role of agroecology in promoting healthier food options. I've conducted a literature review, comparative analysis, policy analysis, and case studies to gain a deeper understanding of this issue and identify potential policy changes and interventions needed to address it. My findings indicate that promoting agroecology and organic food production can reduce the reliance on chemical pesticides and provide healthier food options for children. Furthermore, implementing and expanding farm-to-school programs and prioritizing organic food in school feeding programs can help reduce children's exposure to pesticide residues. By raising public awareness and investing in research on the health impacts of pesticide residues, we can work towards creating a safer and healthier food system for future generations.

We study the Oxford Dictionary Of Chemistry, the seventh edition. We draw the natural logarithm of the number of head entries, normalised, starting with a letter vs the natural logarithm of the rank of the letter, normalised. We conclude that the Dictionary can be characterised by BP(4,$beta H=0$) i.e. a magnetisation curve for the Bethe-Peierls approximation of the Ising model with four nearest neighbours with $beta H=0$, in the absence of external magnetic field, H.$beta$ is $frac{1}{k_{B}T}$ where, T is temperature and $k_{B}$ is the tiny Boltzmann constant.

The oscillation symmetry is applied with success to some physical properties (densities, Boiling points, and Melting points) of different Hydrocarbons: Alkanes, Cycloalkanes, Alkenes, Alkynes, Alkadienes, and Polycyclic Aromatic Hydrocarbons. It is also applied to Hydro Silicons. It allows to tentatively predict possible values for several unknown properties. The same shape of oscillation describes, sometimes after renormalization, the "mass data" of several particle families, nuclei families and Alkane Melting Point "data". The periods of oscillation exhibit discret values as if they are quantified.

Chlorine dioxide, ClO2, a non-patentable substance, is a molecule composed by two of the most disinfectant elements found in nature, chlorine and oxygen, both of them electronegative. As early as 1850, ClO2 has been being used in the oxidation of water and, since 1944, in the treatment of waste water and the bleaching of cellulose. Similarly, oxygen, in the form of hydrogen peroxide, is used to disinfect ambulances, hospital rooms and medical equipment, among other applications. Recently, the Global Health and Life Coalition (GHLC) has reported favourable results in the treatment of COVID-19 using ClO2 under a parameterized protocol design by scientists members of this organization. Other research works carried out in dierent parts of the world sustain the hypothesis that, as a relatively stable radical and as a highly oxidant regardless of the pH in its surroundings, ClO2 and its application in an area so sensitive as human health presents itself as an alternative worth studying further.

Electrochemical reactions depend on the electrochemical interface; between the catalytic surfaces and the electrolytes. To control and advance electrochemical reactions there is a need to develop realistic simulation models of the electrochemical interface to understand the interface from an atomistic point-of-view. Here we present a method for obtaining thermodynamic realistic interface structures, a procedure to derive specific coverages and to obtain ab initio simulated cyclic voltammograms. As a case study, the method and procedure is applied in a matrix study of three Cu facets in three different electrolyte. The results are validated by a direct comparison with experimental cyclic voltammograms. The alkaline (NaOH) electrolyte CV are described by H* and OH*, while neutral (KHCO3) the CO3* species are present and in acidic (KCl) the Cl* species dominate. An almost one-to-one mapping is observed from simulation to experiments giving an atomistic understanding of the interface structure of the Cu facets. The strength of atomistic understanding the interface at electrolyte conditions will allow realistic investigations of electrochemical reactions in future studies.

A simple visible spectrophotometric method is proposed for the determination of ulipristal acetate present in bulk and tablet formulation. The currently proposed method is established based on MBTH oxidation by ferric ions to form an active coupling species (electrophile), followed by its coupling with the ulipristal in acidic medium to form high intensi��ied green colored chromophore having max at 609 nm. Validated the method as per the current guidelines of ICH. Beer’s law was obeyed in the concentration range of 6.25 – 37.50 g mL��1 with a high regression coef��icient (r > 0.999). Reproducibility, accuracy, and precision of the method are evident from the low values of R.S.D. This method can be used in quality control laboratories for routine analysis of ulipristal acetate in bulk drug and pharmaceutical dosage forms.

Polyoxyethylene – 300 (POE) is a well-known biodegradable pharmaceutical polymer. In order to understand the stability of POE and to derive the reaction rate law, the title reaction was carried out in aqueous alkaline medium. Reaction was found to be ��irst order dependent on the concentration oxidant (periodate) and independent of substrate (POE) concentration. A retardation of reaction rate with an increase in hydroxide concentration shows an inverse fractional order in it. Based on the studies of the temperature dependence of reaction, evaluated the activation parameters.

According to all known laws of chemistry, mystopropane should not be able to form, but it does anyway because mystopropane does not care what humans think is impossible. Recent developments in the intense and very mysterious field of isobutane have revealed different forms of this strange molecule that have been shown to be created in new and novel ways that were previously thought to be impossible. Mystopropane is structurally very similar to isobutane and may look the same to the naked eye (considering one cannot see a molecule with the naked eye). The differences between isobutane and mystopropane will be revealed throughout this study, which will include the in-depth research of scientists like Daved Von Walkerheim II and Devang Deepak. The “Great Kacklehauser-Shimeryton Debate” will also be thoroughly mentioned because of its contributions to the continued research on mystopropane.

The existence of a disentangling mathematical transformation of wave function in a Coulomb entangled state of charged molecular radicals, reveals a new chapter to the Einstein- Schrodinger discussion about entanglement.

Contents<br><br> Part I <br> O(j) is not fully equivariant if j is odd <br> Representations of SO3<br> Eigenfunctions of the Laplacian<br> Attempts to explain the periodic table<br> Attempts to explain atomic spectra<br><br> Part II <br> Three corrections to the fine structure<br> A discussion of perturbation theory <br> Half-integer values of l – first explanation<br> Generalities about the Hamiltonian formulation<br> Schroedinger’s function W<br> Half-integer values of l – other explanations<br> The atom<br> Schroedinger’s choice of solutions<br> Residues<br> The canonical divisor and j quantum number<br> Intuitive description of polarization<br> Relation between smooth and holomorphic Laplacian operators<br> A coincidence about the periodic table<br> Linear systems of wave forms<br> Hodge theory<br> The Levi-Civita action is not Lagrangian for its Riemann metric<br> Foundations<br> Unification of the various coupling schemes<br> Discussion of the problem of non-convergent integrals<br> The ethics of science<br> First concepts of the Lamb shift<br> A question about Pauli exclusion<br> The notion of probability<br> Concluding remark<br> False fine structure<br> Electron spin and Pauli exclusion<br> It was not the right conclusion<br>

Experiments were conducted to optimize the growth parameters of perovskite structure of sodium tantalate in energy efficient hydrothermal process. We have succesfully grown sodium tantalate nanocubes at low temperature of 140oC for 15 hours in rich alkaline atmosphere. It contains orthorhombic crystal system of perovskite structure with an average size of 80 nm. The morphological, compositional, structural, and thermal properties of as-synthesized nanocubes were characterized by scanning electron microscope (SEM), x-ray powder diffraction (XRD), and thermal gravimetric analysis (TGA) techniques.

Silver nanoparticles (Ag-NPs) are among the most medical applications nanomaterials mainly due to its antimicrobial effect, plasmon resonance and its capacity to impregnate polymeric materials. Recently Ag-NPs have been used in water treatment systems, central venous catheters, burn dressing, as well as in biosensors for detecting levels of p53 protein associated with cancer development. Moreover, the Ag-NPs have been studied for being potentially dangerous to humans and environment. Ag-NPs are transformed under the ecosystems conditions and may even increase their aggressiveness. The aim of this paper is to investigate the current state of knowledge about the bactericidal effect of Ag-NPs, the main synthesis methods, its application based on antibiotic capacity, Ag-NPs environmental transformations and their impact on the human.

This article presents a high-throughput computer program, called EasyDD, for batch processing, analyzing and visualizing of spectral data; particularly those related to the new generation of synchrotron detectors and X-ray powder diffraction applications. This computing tool is designed for the treatment of large volumes of data in reasonable time with affordable computational resources. A case study in which this program was used to process and analyze powder diffraction data obtained from the ESRF synchrotron on an alumina-based nickel nanoparticle catalysis system is also presented for demonstration. The development of this computing tool, with the associated protocols, is inspired by a novel approach in spectral data analysis.

In this thesis we investigate high throughput computational methods for processing large quantities of data collected from synchrotrons and their application to spectral analysis of powder diffraction data. We also present the main product of this PhD programme, specifically a software called 'EasyDD' developed by the author. This software was created to meet the increasing demand on data processing and analysis capabilities as required by modern detectors which produce huge quantities of data. Modern detectors coupled with the high intensity X-ray sources available at synchrotrons have led to the situation where datasets can be collected in ever shorter time scales and in ever larger numbers. Such large volumes of datasets pose a data processing bottleneck which augments with current and future instrument development. EasyDD has achieved its objectives and made significant contributions to scientific research. It can also be used as a model for more mature attempts in the future. EasyDD is currently in use by a number of researchers in a number of academic and research institutions to process high-energy diffraction data. These include data collected by different techniques such as Energy Dispersive Diffraction, Angle Dispersive Diffraction and Computer Aided Tomography. EasyDD has already been used in a number of published studies, and is currently in use by the High Energy X-Ray Imaging Technology project. The software was also used by the author to process and analyse datasets collected from synchrotron radiation facilities. In this regard, the thesis presents novel scientific research involving the use of EasyDD to handle large diffraction datasets in the study of alumina-supported metal oxide catalyst bodies. These data were collected using Tomographic Energy Dispersive Diffraction Imaging and Computer Aided Tomography techniques.

In this study, supercritical fluid extraction has been successfully applied to a sequential fractionation of fatty acids and polyphenols from wine wastes (2 different vitis vinifera grapes). To this aim, in a 1st step just fatty acids were extracted and in a 2nd one the polyphenols. The variables that affected to the extraction efficiency were separately optimized in both steps following an experimental design approach. The effect of extraction temperature flow, pressure, and time were thoroughly evaluated for the extraction of fatty acids, whereas the addition of methanol was also considered in the case of the polyphenols extraction. A quantitative extraction with high efficiency was achieved at a very short time and low temperatures. Concerning quantification, fatty acids were determined by means of gas chromatography coupled to mass spectrometry after a derivatization step, whereas the polyphenols were analyzed by means of high performance liquid chromatography coupled to tandem mass spectrometry and the Folin–Ciocalteu method.

2D a-MoO3 was synthesized using a facile, inexpensive and scalable liquid-phase exfoliation method. 2D a-MoO3/SWCNT (85 wt%/15 wt%) composite films were manufactured by vacuum filtration and their energy storage properties were investigated in a LiClO4/propylene carbonate electrolyte in a 1.5 V to 3.5 V vs. Li+/Li electrochemical window. Cyclic voltammetry showed typical ion intercalation peaks of a-MoO3 and a capacitance of 200 F/g was achieved at 10 mV/s and 82 F/g at 50 mV/s. The composite electrodes achieved a capacitive charge storage of 375 C/g and a diffusion-controlled maximum charge storage of 703 C/g. The latter being superior to the charge storage achieved by previously reported mesoporous a-MoO3, produced using more cumbersome multi-step templating methods, and a-MoO3 nanobelts . This superior Li-ion intercalation charge storage was attributed to the shorter ion-transport paths of 2D a-MoO3 as compared to other nanostructures. Galvanostatic charge-discharge experiments showed a maximum charge storage of 123.0 mAh/g at a current density of 100 mA/g.

Torrefaction is mild thermo-chemical process similar to pyrolysis, that can be applied to biomass to improve energy density and hydrophobicity. Comparison was made between original and torrefied forms of hazelnut shell agricultural waste biomass, when these materials were subjected to gasification using a “bench-scale” fluidised bed gasifier. Results indicated that a simplified torrefaction process was successful in physical transformation of the hazelnut shell and that the resultant syn-gas was of a relatively higher calorific value, together with lower tar content. Keywords: biomass, TGA, thermogravimetry, thermogravimetic analysis, gasification, fluidisation

In their article, Gharagheizi et al. [J. Chem. Eng. Data 2011, 56, 1741-1750] claim to develop a model to predict the molecular diffusivity of "nonelectrolyte organic compounds" in water using an artificial neural network-group contribution method. Many of these compounds have ionizable functionalities with pKa values that result in either substantial or effectively complete ionization in water (making them electrolytes, in contrast to the claims of Gharagheizi et al.). Consequently, the model developed and applied by Gharagheizi et al. does not computationally model the actual speciation(s) of each compound expected to be present under the experimental conditions for which the underlying data has been obtained and erroneously classifies many organic compounds as non-electrolytes.

In their article (Cliff et al., J. Sens. Stud., 2011, 26, 184-196), the authors plot the log mean aroma threshold concentrations for three sulfur aroma compound analytes on the y-axis against the qualitative descriptors of the wine (i.e., "model," "neutral," and "fruity") on the x-axis, and proceed to fit three log-linear regression models through the sets of data. The statistical validity of this exercise seems problematic (particularly with only three datapoints, and four significant figures in the resulting quoted regression constants), and the reason behind this choice of data analysis is unclear. Some type of statistical test (e.g., ANOVA) designed to investigate relative trend differences between categorical variables would perhaps be more appropriate, especially when such nebulous categorical descriptors as "neutral" and "fruity" are being employed along the x-axis and ordered in an arbitrary manner.

In their study, Wang et al. [Environ. Chem. 2011, 8, 389] use the COSMOtherm software program in an attempt to shed some insights into the physicochemical properties of various poly- and perfluorinated compounds. During the conformation dependent pKa investigations on n-perfluorooctanoic acid (PFOA), the authors appear to make a critical error in their analyses. Wang et al. appear to have allowed a transition from an acid form geometry to a very different anionic form geometry, which is not a correct way of calculating free energy changes during acid dissociation. This error explains why these authors obtained widely ranging conformation dependent pKa values (0.9 to 2.9) for PFOA dissociation. As has been previously shown [Rayne and Forest, J. Mol. Struc. THEOCHEM 2010, 949, 60], there are negligible conformation dependent effects on the pKa value of PFOA.

In their manuscript, Gramatica et al. [Mol. Inf. 2012, 31, 817-835] claim to conduct quantitative structure-activity relationship (QSAR) modeling on a suite of triazoles, benzotriazoles, and additional azo-aromatic compounds. However, a number of the compounds examined by these authors do not appear to be triazoles, benzotriazoles, or other azo-aromatic compounds. In some cases, the authors also appear to publish incorrect molecular structures which may affect the structural descriptors employed for QSAR development.

In their article, Bronner and Goss [Environ. Sci. Technol., 2011, 45, 1307-1312] investigate the pH dependence of organic chemical sorption to soil organic matter. The authors report a log Koc value for benzoyl chloride in aqueous solution, despite this compound having a known hydrolysis half-life of only 16 seconds in water. This timeframe is far too short to allow the measurement of any equilibrium based partitioning coefficients. Consequently, one suspects that the log Koc value reported for benzoyl chloride is likely that of its hydrolysis product: benzoic acid. The authors also may have chosen two experimental conditions (pH 4.5 and 7.2) between which the ionization state of the carboxylic acids in the organic matter may have changed very little, and could instead have remained in effectively the same net ionization state between the two experimental pH endpoints. Thus, there does not appear to be sufficient evidence in this work to support the general claim therein that "protonation/deprotonation of carboxylic groups in humic matter has no significant influence on sorption ... even for polar organic molecules."

In their article, Sacan et al. [J. Chem. Inf. Comput. Sci. 2004, 44, 985-992] construct a quantitative structure-property relationship model to predict the bioconcentration factors of purportedly nonionic organic compounds. A number of the compounds examined by these authors are not nonionic as claimed, but instead have associated pKa values that would render the molecules significantly, and - in some cases - effectively entirely, ionized under conditions relevant for bioconcentration in freshwater and/or marine aquatic systems.

In their article, Gotz et al. [Environ. Sci. Technol., 2008, 42, 3690-3696] use three different multimedia contaminant fate models to analyze the impact of implementing a two-particle-size polyparameter linear free energy relationship approach on metrics of persistence and long-range transport, and on calculated concentrations of semivolatile organic chemicals in the Arctic. One of the twelve compounds investigated is 2,4-D (2,4-dichlorophenoxyacetic acid), which is effectively entirely dissociated in aqueous systems. The authors do not appear to have considered the ionization of 2,4-D during their multimedia modeling exercises, particularly the effects of ionization on octanol-water and air-water partitioning behavior. Consequently, all modeling results presented for 2,4-D appear to be in significant error and should not be employed for risk assessment purposes.

In their article, Arnot and Mackay [Environ. Sci. Technol., 2008, 42, 4648-4654] use 200 chemicals from the Canadian Domestic Substances List (DSL) to illustrate a model that integrates persistence, bioaccumulation, toxicity, and quantity information for a specific substance to assess chemical exposure, hazard, and risk. The authors claim that the DSL chemicals used in their study are not expected to appreciably ionize at environmental pH. In contrast, a number of the compounds in this study have ionizable functional groups with environmentally relevant pKa values, meaning the corresponding partitioning properties are highly pH dependent, thereby rendering the modeling approach applied by these authors subject to a fatal conceptual and practical flaw. In addition, several compounds in the authors' dataset are expected to hydrolyze rapidly in aquatic systems, resulting in negligible environmental persistence.

In their article, Qin et al. [Mol Divers (2010) 14:67-80] construct a quantitative structure-property relationship model to predict the bioconcentration factors of purportedly nonpolar organic compounds. A number of the compounds examined by these authors are not nonpolar as claimed, but instead have associated pKa values that would render the molecules significantly, and - in some cases - effectively entirely, ionized under conditions relevant for bioconcentration in freshwater and/or marine aquatic systems.

In their article, Endo and Goss [Chem. Res. Toxicol. 2011, 24, 2293-2301] claim to measure the bovine serum albumin water partition coefficients for 83 structurally diverse neutral organic chemicals and correlate the resulting values against corresponding octanol-water partition coefficients and polyparameter linear free energy relationship models based on descriptors for the neutral forms of each compound. However, several compounds in the authors' dataset would be significantly ionized under the experimental conditions being modeled against, and such ionization must be accounted for in any serum albumin binding modeling efforts.

In their article, Charif et al. [J. Mol. Struct. THEOCHEM 818 (2007) 1] used the B3LYP/6-311++G(d,p) density functional level of theory to estimate gas phase standard state (298.15 K, 1 atm) free energies of acid dissociation (ΔacidG°(g)) for 21 carbon acids. These authors then examined correlations between their B3LYP/6-311++G(d,p) ΔacidG°(g) values and corresponding experimental aqueous pKa measurements. Large errors are evident between experimental values and the B3LYP/6-311++G(d,p) calculated ΔacidG°(g) for propanedioic acid, diethyl ester, dimedone, isopropylidene malonate, barbituric acid, and toluene from this study. The findings call into question the generality of the correlation between ΔacidG°(g) and aqueous experimental pKa values for carbon acids proposed by Charif et al., and also highlight the need for additional studies to investigate what other carbon acid moieties may be outliers. In the present case, either the experimental aqueous pKa of toluene in the literature is incorrect, or the quantitative structure-property relationship proposed in Charif et al. is subject to large outliers that greatly diminish its broad applicability.

In their article, Montero-Campillo et al. [J. Phys. Chem. A, 114 (2010) 10148-10155] use the B3LYP density functional with the 6-311+G(d,p) basis set to calculate the relative thermodynamic stabilities of the 89 linear and branched perfluorooctane sulfonic acid (PFOS) isomers in their molecular acid and dissociated anionic forms for the gas phase and aqueous and n-octanol solvent phases. A substantial body of work over the past decade has clearly demonstrated the inability of the B3LYP functional (and the majority of other widely employed density functionals) to accurately represent the relative thermodynamic stabilities of linear and branched alkanes (including perhydro, poly- and perhalogenated, and other functionalized derivatives). It has been specifically demonstrated using a range of theoretical methods (semiempirical, Hartree-Fock [HF], various density functionals, and second order Moller-Plesset perturbation theory) that the B3LYP branching error for perhydroalkane isomerizations also applies to perfluoroalkanes, and particularly to classes of compounds such as the 89 PFOS isomers, as well as the perfluoroalkanoic acids and perfluoralkyl sulfonyl/acyl fluorides in their acid and (where applicable) anionic forms. Consequently, the relative thermodynamic stabilities of the molecular acid and anionic PFOS isomers at the B3LYP/6-311+G(d,p) level of theory put forward by Montero-Campillo et al. are in substantial error, and the authors and readers are referred elsewhere to more accurate calculations.

In their work, Hu et al. [Environ. Sci. Technol., 2011, 45, 3635-3642] investigate the oxidation of three antibiotics (ciprofloxacin, lincomycin, and trimethoprim) by potassium permanganate in buffered solutions at pH 7. The authors propose detailed mechanistic pathways for the oxidation of these substrates, but apparently do not consider the acid/base behavior of the compounds under consideration, resulting in erroneous mechanistic interpretations throughout the manuscript.

In his article, Gharagheizi [Ind. Eng. Chem. Res. 2012, 51, 2797-2803] claims to develop a novel three-parameter equation for the calculation/prediction of the diffusion coefficient of nonelectrolyte organic compounds in water at infinite dilution. In contrast, many of the compounds investigated in this work are electrolytes in pure water at infinite dilution. Consequently, the molecular modeling efforts on the non-ionized molecular speciation of each compound were - in many cases - conducted on species that would not be dominantly present under the experimental conditions the modeling efforts are being developed against.

In their article, Wong and Wania [J. Environ. Monit., 2011, 13, 1569-1578] claim to estimate the partitioning properties (air-water partition coefficients and soil organic carbon-water partition coefficients) of twenty neutral organic chemicals using poly-parameter linear free energy relationships. Five of the 20 compounds in this study have ionizable functional groups with environmentally relevant pKa values, meaning the corresponding partitioning properties are highly pH dependent, thereby rendering the modeling approach applied by these authors subject to a fatal conceptual and practical flaw.

In their article, DeBruyn and Gobas [2007. Environ Toxicol Chem 26:1803-1808] claim to "present a compilation and meta-analysis of published data to estimate the relative sorptive capacities of animal proteins and lipids for neutral organic chemicals." However, the dataset of these authors contains compounds that would be effectively entirely ionized at physiological pH values, rendering the assumption of neutrality and any subsequent analyses based thereupon incorrect.

In their article, Bhhatarai and Gramatica [Water Res. 45, 2011, 1463-1471] employ a quantitative structure-property relationship approach to model the physico-chemical properties of compounds they refer to as benzotriazoles, and to subsequently screen these compounds for environmental partitioning behavior. A substantial number of these compounds are not benzotriazoles and do not have similar properties as benzotriazoles. Consequently, it appears that the approach, assumptions, and results in this work must be viewed as potentially fundamentally flawed.

In their study, Bhhatarai et al. [Mol. Inf. 2010, 29, 511-522] develop quantitative structure-activity relationships (QSARs) for the inhibition of HIV protease by 158 so-called 4-OH cycloalkyl-pyranones. A number of compounds termed 4-OH cycloalkyl-pyranones in this work do not appear to be cycloalkyl-pyranones.

In their article, Yemis and Mazza [Yemis and Mazza, 2011, Bioresour. Technol. 102, 7371-7378] study the effects of different Bronsted acids, temperatures, times, substrate concentrations, and pH on the acid-catalyzed conversion of xylose, xylan and straw into furfural by microwave-assisted reaction. The authors appear to incorrectly classify phosphoric acid as a mineral acid, and claim to achieve pH values in solutions of acetic and formic acid below the apparent theoretical limits.

The partitioning behavior of disparlure ((7R,8S)-7,8-epoxy-2-methyloctadecane) - a sex pheromone of the gypsy moth, Lymantria dispar - between aqueous solutions and the organic solvents chloroform and n-heptane has been re-evaluated. Prior estimates from the literature of the aqueous-organic solvent partitioning coefficients (log P) for disparlure in these two solvent systems appear to have been underestimated by about 5-6 orders of magnitude. In the current work, we provide corrected log P(chloroform/water) and log P(heptane/water) values for disparlure of 9.87 and 9.15, respectively.

In an earlier study (Kelly et al., PNAS, 2009, 106, 22346-22351), spatial patterns for the concentrations of particulate matter, particulate polycyclic aromatic compounds (PAC), and dissolved PAC in the snowpack around the Syncrude and Suncor upgrader facilities near the oil sands development at Fort McMurray, Alberta, Canada were determined. A reassessment of the datasets employed in this work yields significantly different deposition rates (by up to an order of magnitude) than reported, as well as reveals substantial sensitivity in deposition rate estimates depending on a range of equally valid regression types chosen. A high degree of uncertainty remains with regard to the quantities of particulate matter and PAC being deposited in the Athabasca River watershed from oil sands related activities.

The hypertorus electron model is applied to the chemical bond. As a consequence, the bond topology can be determined. A linear correlation is found between the normalized bond area and the bond energy. The normalization number is a whole number. This number is interpreted as the Lewis's electron pair. A new electron distribution in the molecule follows. This discovery prompts to review the chemical bond, as it is understood in chemistry and physics.