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Definition
| the angles (in degrees) defined by lines joining the enters of two atoms to a third atom to which they are covalently bonded |
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Definition
| shape of the molecule; defined by the lowest energy arrangement of its atoms in three-dimensional space |
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Term
Valence Shell Electron-Pair Repulsion
VSEPR |
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Definition
| predicts the arrangement of valence electron pairs around a central atoms that will minimize their mutual repulsion to produce the lower energy orientations |
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Definition
| the number of atoms bonded to the central atom plus the number of lone pairs of electrons on the central atom |
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Definition
| results when the bond angle between three atoms is 180 |
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Term
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Definition
| has a SN of 3 for the central atom of a molecule with no lone pairs and bond angles of 120 |
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Term
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Definition
| has a SN of 4 for the central atom of a molecule with no lone pairs and bond angles of 109.5 |
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Term
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Definition
| has a SN of 5 for the central atom of a molecule with no lone pairs; three atoms occupy equatorial sites in the plane around the central atom with ideal bond angles of 120 and the other two atoms occupy axial sites above and below the central atom with a bond angle of 180 |
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Term
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Definition
| has a SN of 6 for the central atom of a molecule with no lone pairs; all six sites are equivalent and the ideal bond angle for these atoms is 90 |
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Term
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Definition
| describes the arrangement of atoms and lone pairs of electrons about a central atom |
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Definition
| two covalently bonded atoms with different electonegativites have partial electrical charges of opposite sign |
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Definition
| a measured value that defines the extent of separation of positive and negative charge centers in a covalently bonded molecule; a quantitative expression of the polarity of a molecule |
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Definition
| assumes that covalent bonds form when orbitals on different atoms overlap or occupy the same region in space |
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Term
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Definition
| a covalent bond in which the highest electron density lies between the two atoms along the bond axis connecting them |
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Term
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Definition
| the mixing of atomic orbitals to generate new set of orbital that then are available to overlap and form covalent bonds with other atoms |
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Term
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Definition
| a tetrahedral orientation of valence electrons is achieved by forming four of these orbitals |
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Term
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Definition
| the trigonal planar orientation of valence electrons is achieved by this |
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Term
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Definition
| six of these orbitals point towards the vertices of an octahedron |
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Term
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Definition
| five of these orbitals have lobes that point toward the vertices of a trigonal bipyramid |
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Term
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Definition
| electron density is greatest above and below or in front of an behind the bonding axis |
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Term
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Definition
| electrons in the pi bonds in a system with alternating single and double bonds can be this over several atoms or even an entire molecule |
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Term
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Definition
| molecules consisting of flat rings with pi electron cloud delocalized above and below the plan of molecules |
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Term
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Definition
| a bonding theory based on the mixing of atomic orbitals of similar shapes and energies to form molecular orbitals that belong to the molecule as a whole |
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Term
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Definition
| a regions of characteristic shape and energy where electrons in a molecule are located |
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Definition
| destabilize the molecule because they do not increase the electron density between nuclear centers and therefore do not participate in holding the molecule together |
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Term
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Definition
| when the region of highest density lies along the bond axis between two nuclear centers, electrons in sigmas orbitals form sigma bonds |
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Term
| Molecular Orbital Diagram |
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Definition
| energy level diagram; shows the relative energies and electron occupancy of the molecular orbitals for a molecule |
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Term
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Definition
| atoms, ions, and molecules have no unpaired electrons and are weakly repelled by a magnetic field |
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Term
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Definition
| atoms, ions, and molecule contain at least one unpaired electron and are attracted by an external magnetic field; the strength of the attraction increase as the number of unpaired electrons increases |
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