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Bonding Theories 8.3 This car is being painted by a process called electrostatic spray painting. The negatively charged droplets are attracted to the auto body. You will learn how attractive and repulsive forces influence the shapes of molecules.
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Chemistry 8.3
8.3
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Bonding Theories
This car is being painted by a process called electrostatic spray painting. The negatively charged droplets are attracted to the auto body. You will learn how attractive and repulsive forces influence the shapes of molecules.
8.3
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Bonding Theories >
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8.3 Molecular Orbitals
Molecular Orbitals
How are atomic and molecular orbitals related?
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Bonding Theories >8.3 Molecular Orbitals
When two atoms combine, the molecular orbital model assumes that their atomic orbitals overlap to produce molecular orbitals, or orbitals that apply to the entire molecule.
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Bonding Theories >8.3 Molecular Orbitals
Just as an atomic orbital belongs to a particular atom, a molecular orbital belongs to a molecule as a whole.
A molecular orbital that can be occupied by two electrons of a covalent bond is called a bonding orbital.
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Bonding Theories >8.3 Molecular Orbitals
Sigma Bonds
When two atomic orbitals combine to form a molecular orbital that is symmetrical around the axis connecting two atomic nuclei, a sigma bond is formed.
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Bonding Theories >8.3 Molecular Orbitals
A Sigma Bond
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Bonding Theories >8.3 Molecular Orbitals
When two fluorine atoms combine, the p orbitals overlap to produce a bonding molecular orbital. The F—F bond is a sigma bond.
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Bonding Theories >8.3 Molecular Orbitals
Pi Bonds
In a pi bond (symbolized by the Greek letter ), the bonding electrons are most likely to be found in sausage-shaped regions above and below the bond axis of the bonded atoms.
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Bonding Theories >8.3 Molecular Orbitals
Pi-bonding Molecular Orbital
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Bonding Theories >
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8.3 VSEPR Theory
VSEPR Theory
How does VSEPR theory help predict the shapes of molecules?
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Bonding Theories >8.3 VSEPR Theory
The hydrogens in a methane molecule are at the four corners of a geometric solid. All of the H—C—H angles are 109.5°, the tetrahedral angle.
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Bonding Theories >8.3 VSEPR Theory
The valence-shell electron-pair repulsion theory, or VSEPR theory, explains the three-dimensional shape of methane.
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Bonding Theories >8.3 VSEPR Theory
According to VSEPR theory, the repulsion between electron pairs causes molecular shapes to adjust so that the valence-electron pairs stay as far apart as possible.
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Bonding Theories >8.3 VSEPR Theory
The measured H—N—H bond angle is only 107°.
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Bonding Theories >8.3 VSEPR Theory
The measured bond angle in water is about 105°.
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Bonding Theories >8.3 VSEPR Theory
The carbon dioxide molecule is linear.
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Bonding Theories >8.3 VSEPR Theory
Nine Possible Molecular Shapes
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Bonding Theories >
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8.3 Hybrid Orbitals
Hybrid Orbitals
In what ways is orbital hybridization useful in describing molecules?
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Bonding Theories > Hybrid Orbitals
Orbital hybridization provides information about both molecular bonding and molecular shape.
In hybridization, several atomic orbitals mix to form the same total number of equivalent hybrid orbitals.
8.3
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Bonding Theories >8.3 Hybrid Orbitals
Hybridization Involving Single Bonds
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Bonding Theories >8.3 Hybrid Orbitals
Hybridization Involving Double Bonds
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Bonding Theories >8.3 Hybrid Orbitals
Hybridization Involving Triple Bonds
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Bonding Theories > Hybrid Orbitals
Simulation 7 Compare sp, sp2, and sp3 hybrid orbitals.
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Section Quiz
-or-Continue to: Launch:
Assess students’ understanding of the concepts in Section 8.3.
8.3 Section Quiz.
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8.3 Section Quiz.
1. A molecular orbital belongs to a
a. specific atom.
b. molecule as a whole.
c. specific pair of atoms.
d. central atom.
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8.3 Section Quiz.
2. VSEPR theory enables prediction of 3-dimensional molecular shape because the valence electron pairs
a. are attracted to each other.
b. form molecules with only four possible shapes.
c. stay as far apart as possible.
d. always form tetrahedral shapes.
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3. Orbital hybridization provides information about
a. both molecular bonding and molecular shape.
b. both molecular bonding and bond energy.
c. neither molecular bonding nor molecular shape.
d. neither molecular bonding nor bond energy.
8.3 Section Quiz.
END OF SHOW
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