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	VSEPR - Molecular Models
		Valence Shell Electron Pair Repulsion theory (VSEPR) is a set of rules whereby the chemist may predict the shape of an isolated molecule.
		The ideal electronic symmetry of a molecule consisting of a central atom surrounded by a number of substituents (bonded atoms and non-bonding electrons) is characteristic of the total number of substituents, and is determined solely by geometric considerations -- the substituents are arranged so as to maximize the distances amongst them.
		VSEPR is useful for predicting the shape of a molecule when there are between 2 and 6 substituents around the central atom (the case of one substituent is not discussed because it is trivial -- the only possible shape for such a molecule is linear).
	chemlabs.uoregon.edu /GeneralResources/models/vsepr.html (520 words)

	Valence-Shell Electron-Pair Repulsion Theory (VSEPR)
		The VSEPR theory assumes that each atom in a molecule will achieve a geometry that minimizes the repulsion between electrons in the valence shell of that atom.
		The VSEPR theory predicts that the valence electrons on the central atoms in ammonia and water will point toward the corners of a tetrahedron.
		When we extend the VSEPR theory to molecules in which the electrons are distributed toward the corners of a trigonal bipyramid, we run into the question of whether nonbonding electrons should be placed in equatorial or axial positions.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch8/vsepr.html (1344 words)

	[No title]
		This is an important issue because VSEPR is generally taught at the expense of more comprehensive and important bonding theories such as molecular orbital theory.
		I think it is important for the community of undergraduate chemistry teachers to discuss the question of whether or not VSEPR belongs in the chemistry curriculum.
		This approach leads to the impression that electron-electron repulsions determine the geometries of molecules, because the model is presented in the form of an explanation and structures are used to confirm the model.
	www.users.csbsju.edu /~frioux/vsepr/NVSEPR.htm (1291 words)

	VSEPR Model and Molecular Geometry
		VSEPR Theory- The valence-shell electronic-pair repulsion (VSEPR) model is an approach of using the number of electrons surrounding a central atom to study the molecular structures, based on the theory that the structure around a given atom is determined principally by minimizing electron-pair repulsions.
		Use the VSEPR geometry table to predict the geometry of the molecule.
		The VSEPR structure of the input molecule is displayed, along with the name of the geometrical structure.
	www.molecularsoft.com /data/help/Chemical_Bonds-VSEPR.htm (400 words)

	Molecular Geometry
		At this point we are ready to explore the three dimensional structure of simple molecular (covalent) compounds and polyatomic ions.
		VSEPR focuses on the positions taken by the groups of electrons on the central atom of a simple molecule.
		Here are some VSEPR animations that do not require a plug-in to view.
	intro.chem.okstate.edu /1314F00/Lecture/Chapter10/VSEPR.html (1695 words)

	VSEPR
		In this helpdesk section we'll discuss what VSEPR means, what it's all about, and how you can use a great big flow chart to figure out the bond angles, shapes, and hybridizations of various covalent compounds.
		This is because covalent bonds consist of electrons, and electrons don't like to hang around next to each other much because they have the same charge.
		Now, one problem with the whole VSEPR thing is that if you have four things stuck to carbon, for example, there are no orbitals that want to get 109.5 degrees apart from each other (109.5 degrees corresponds to the geometric maximum distance the atoms can get apart).
	misterguch.brinkster.net /VSEPR.html (934 words)

	Molecular Models & VSEPR Theory
		Valence Shell Electron Repulsion Theory (VSEPR) is often used to predict particle shape from a Lewis dot formula.
		The VSEPR theory focuses on the idea that electrons repel one another and that these repulsions are smallest when the electron pairs or groups of electron pairs are as far apart as possible.
		Electron groups in the VSEPR model are lone pairs, single bonds, double bonds, triple bonds and single electrons as in NO. The No molecule is an exception to the octet rule.
	www.800mainstreet.com /vsepr/vsepr.html (2238 words)

	Chemical Bonding: Geometry
		The fundamental idea of VSEPR thoery is that these regions of negative electric charge will repel each other, causing them (and thus the chemical bonds) to stay as far apart as possible.
		The application of VSEPR theory then reduces to the simple problem of naming (and visualizing) the geometric shapes associated with various numbers of points surrounding a central point (the central atom) at the greatest possible angles.
		This makes no difference to VSEPR theory; the central carbon atom is still joined to two other atom, and the coordination number is still only 2.
	www.chem1.com /acad/webtext/chembond/cb05.html (2667 words)

	InfoDense - Web - Vsepr Models (Site not responding. Last check: 2007-10-20)
		The VSEPR model counts both bonding and nonbonding (lone) electron pairs, and...
		the whole goal of the VSEPR model is to correctly determine the...
		In VSEPR theory, the position of bound atoms (ligands) and electron pairs are...
	www.infodense.com /topic?i=Vsepr%20Models (184 words)

	ChemTeam: VSEPR Theory of Molecular Geometry (Site not responding. Last check: 2007-10-20)
		The electrons (both in pairs and singles as you will see) are "attached" to a central atom in the molecule and can "pivot" freely on the atom's surface to move away from the other electrons.
		VSEPR uses a set of letters to represent general formulas of compounds.
		The VSEPR Model of Molecular Geometry (1991) by Ronald J. Gillespie and Istvàn Hargittai.
	www.miracosta.edu /home/dlr/other/VSEPR-Intro.html (583 words)

	The VSEPR Model
		The valence-shell electron pair repulsion (VSEPR) model gives us a way of creating the correct 3-D model of a molecule by helping us determine the correct placement of atoms and nonbonding electrons in the molecule based on the repulsions of electrons in the molecule.
		Here's the take-home message: The goal of the VSEPR model is to arrange the electron pairs around the central atom so that there is the least amount of repulsions among them.
		As mentioned before, the whole goal of the VSEPR model is to correctly determine the position of the atoms in a molecule based on electron repulsion.
	stezlab1.unl.edu /reu1999/dputn226/ChemHelp/RET_Web_Pages/VSEPR/vsepr_model.htm (1010 words)

	Valence Shell Electron Pair Repulsion, VSEPR
		VSEPR 'theory' only says that ligands arrange themselves about an atomic centres so as to maximise spherical symmetry.
		Ronald Gillespie, one of the two developers of modern VSEPR theory, ascribes the VSEPR effect to the Pauli exclusion principle: R. Gillespie and P. Popelier, Chemical Bonding and Molecular Geometry, OUP, 2001, Chapter 4 (Amazon).
		Valence bond theory and VSEPR both predict methane to be tetrahedral, even though the methodologies are totally different: valence bond theory directly manipulates the atomic orbitals while VSEPR simply says that the methane will adopt the most spherically symmetric conformation.
	www.meta-synthesis.com /webbook/45_vsepr/VSEPR.html (1803 words)

	Lesson Plan – VSEPR Theory
		Use VSEPR theory to explain geometry of molecules.
		The VSEPR and Hybridization handout aids students in classifying types of molecules.
		Students will complete a worksheet using the VSEPR theory to predict the shapes of molecules.
	www.duke.edu /~ljw5/vsepr.htm (336 words)

	VSEPR - A Summary (Site not responding. Last check: 2007-10-20)
		Valence Shell Electron Pair Repulsion (VSEPR) theory allows the Chemist to predict the 3-dimensional shape of molecules from knowledge of their Lewis Dot structure.
		In VSEPR theory, the position of bound atoms (ligands) and electron pairs are described relative to a central atom.
		Once the ligands and lone pair electrons are positioned, the resulting geometrical shape presented by the atoms only (ignoring lone pairs) is used to describe the molecule.
	mc2.cchem.berkeley.edu /VSEPR (114 words)

	ChemTeam: VSEPR Theory of Molecular Geometry (Site not responding. Last check: 2007-10-20)
		The electrons (both in pairs and singles as you will see) are "attached" to a central atom in the molecule and can "pivot" freely on the atom's surface to move away from the other electrons.
		VSEPR uses a set of letters to represent general formulas of compounds.
		The VSEPR Model of Molecular Geometry (1991) by Ronald J. Gillespie and Istvàn Hargittai.
	dbhs.wvusd.k12.ca.us /webdocs/VSEPR/VSEPR-Intro.html (583 words)

	Valence Shell Electron Repulsion Theory (Site not responding. Last check: 2007-10-20)
		VSEPR theory states that the electrons in a molecule repel each other, so the orbitals containing those electrons are oriented as far away from each other as possible.
		VSEPR can be used to predict the structures around atoms with more than two things attached: for example, the methane molecule CH has the four hydrogens at the tips of a tetrahedron, with the angles between the bonds = 109.5
		Lone pairs affect the molecular geometry, but VSEPR does a good job predicting structures with lone pairs as well.
	www.cartage.org.lb /en/themes/Sciences/Chemistry/Inorganicchemistry/Informationbonding/bondingindex/VSEPR/vsepr.htm (319 words)

	VSEPR and bond angles
		The VSEPR model does a remarkably good job of predicting molecular geometries in a general way, based on symmetry arguments and the all-important idea of electron pair repulsions.
		We have stated (see page 82 in the text) that lone pairs "tend to occupy more space" than bonding pairs, but with one more idea, we can be quantitative about the effect of lone pairs on the final geometry.
		First, the VSEPR idea that lone pairs repel bonding pairs, distorting bond angles away from (usually to values smaller than) the ideal angles is valid.
	www.dartmouth.edu /~genchem/0102/spring/6winn/VSEPR2.html (617 words)

	Theory of Atoms in Molecules: The Laplacian of the Electron Density and the Lewis and VSEPR Models
		This model is secondary only to the atomic hypothesis itself in understanding chemical bonding and reactivity and the geometry of molecules, the latter as predicted in terms of the localized electron pairs assumed in the VSEPR model.
		The uniform sphere of charge concentration present in the valence shell of a free atom is distorted upon chemical combination to form local maxima and minima.
		In the axial plane there are three bonded charge concentrations and a fourth apparent maximum which is actually another view of the (3,-1) critical point between the two non-bonded maxima, that is, a critical point with one positive curvature.
	www.chemistry.mcmaster.ca /faculty/bader/aim/aim_5.html (984 words)

	VSEPR - Valence Shell Electron Pair Repulsion Theory (Site not responding. Last check: 2007-10-20)
		To deduce the shape of a molecule it is necessary to know the number of electron pairs around the central atom, therefore an appropriate Lewis structure is required.
		The notations AX E, etc. are referred to as VSEPR formulas.
		They are generic formulas indicating the number of atoms (X) and nonbonding pairs of electrons (E) attached to the central atom (A).
	faculty.salisbury.edu /~dfrieck/212/vsepr.htm (997 words)

	Valence Shell Electron Pair Repulsion Models
		The Valence-Shell Electron-Pair Repulsion (VSEPR) models consider the unshared pairs (or lone electron pairs) and the bonding electrons.
		The VSEPR model counts both bonding and nonbonding (lone) electron pairs, and call the total number of pairs the steric number (SN).
		VSEPR Illustration: View and manipulate molecular models gives excellent graphics, and you may enjoy seeing some of the graphics of the molecules.
	www.science.uwaterloo.ca /~cchieh/cact/c120/vsepr.html (885 words)

	MOLECULAR STRUCTURE - VSEPR
		The VSEPR method of predicting molecular shapes, allows one to get from a formula of say PF to the three dimensional structure at the left.
		Generally the axial bonds are longer than the equatorial bonds (see the section on hybridization.) Note the bond angles in PF Because of the extra room made possible by the 120° angles in the equatorial positions, lone pairs always take the equatorial positions in TBP structures.
		In the language of VSEPR, the repulsions between the lone pairs, which are always greater than others, are minimized in that position--that is to say the TBP steriochemistry will minimize 90° elecron pair repulsions.
	iweb.tntech.edu /chem101-tf/vsepr_2.html (1486 words)

	VSEPR
		VSEPR is a simple theory used to predict the shape of a molecule.
		VSEPR notation is a common shorthand for the electronic structure.
		In this notation A represents the central atom, X the atom (or group of atoms) bonded to the central atom, and E lone pairs of electrons.
	undergrad-ed.chemistry.ohio-state.edu /VSEPR/index.html (403 words)

	VSEPR
		Before you can use VSEPR theory to predict the shape of a molecule, you must be able to draw a proper Lewis structure for that molecule.
		In terms of VSEPR theory, this means areas of electron density (i.e.
		The shapes of these molecules become obvious when the orbitals are removed as shown in the bottom row of the figure.
	www.usm.maine.edu /~newton/Chy251_253/BasicPrinciples/VSEPR.html (1274 words)

	VSEPR
		Welcome to this introduction to VSEPR rules for the prediction of molecular shape.
		In addition, try the Sheffield Chemputer one component of which is an interactive VSEPR calculator.
		By arrangement with the publisher (Oxford University Press), this introduction to VSEPR is a hypertext version of Chapter 4 in my book on Chemical Bonding, one of the Oxford Chemistry Primers.
	winter.group.shef.ac.uk /vsepr (199 words)

	VSEPR: Understanding Shapes of Molecules
		Valence Shell Electron Pair Repulsion (VSEPR) is a tool that is used to predict molecular geometry.
		According to VSEPR, a good estimate of the molecular geometry can be predicted by totaling the number of bonds and lone-pairs of electrons about the central atom of a molecule.
		In order to introduce VSEPR we will construct a generic template, from which all molecular geometries are derived.
	www.csupomona.edu /~egoldstein/121/VSEPR6.HTM (1734 words)

	VSEPR and Molecular Models
		These suppplemental pages describe what VSEPR is, and how to use VSEPR to make molecular models, how to predict molecular shapes (molecule geometry), and how to predict molecular polarity, based on the number of electron domains and their arrangement around the center atom.
		For our sake, we consider VSEPR electron domains to be any electron region.
		You should print a figure using VSEPR to predict molecule geometry (shape), polarity, and electron domain arrangments for molecules having Three to Six Electron Domains.
	www.miracosta.cc.ca.us /home/dlr/210vsepr.htm (969 words)

	VSEPR Method by G. Dupuis and N. Berland
		This method prolongs in the geometrical shape aspect the description of the chemical bond by G. Lewis (1916).
		The VSEPR method often permits the correct prediction for the local arrangement of electron pairs arround an atom when this one is the central atom without ambiguity but for complex molecules it's more difficult to forsee the global geometry.
		VSEPR - by John J. Nash, Purdue University
	www.faidherbe.org /site/cours/dupuis/vseprev.htm (1731 words)

	VSEPR Theory (Site not responding. Last check: 2007-10-20)
		Although VSEPR theory can be used to predict the shapes of many inorganic molecules it should be used with caution.
		This leaves a lone-pair of s-electrons that is spherically distributed around the atom and doesn't occupy a particular bonding site in accord with VSEPR theory.
		This is in conflict with the trigonal pyramidal geometry predicted by VSEPR theory.
	www.chm.bris.ac.uk /inorg/schools/vsepr/applicability.htm (225 words)

	VSEPR and Molecular Models
		These suppplemental pages describe what VSEPR is, and how to use VSEPR to make molecular models, how to predict molecular shapes (molecule geometry), and how to predict molecular polarity, based on the number of electron domains and their arrangement around the center atom.
		For our sake, we consider VSEPR electron domains to be any electron region.
		You should print a figure using VSEPR to predict molecule geometry (shape), polarity, and electron domain arrangments for molecules having Three to Six Electron Domains.
	www.miracosta.edu /home/dlr/210vsepr.htm (969 words)

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