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About 1923, __ suggested that the properties of electrons in atoms are better explained by treating the electrons as __ rather than __.
 Louis de Broglie
 waves
 particles

Two kinds of waves and examples
 traveling: sound waves that carry thunderclap and water waves
 Standing waves (vibrate in a fixed location): inside an organ pipe

An electron in an atomic orbital is like a __: __
stationary, bound vibration: a standing wave

The orbital (take, for ex, the 1s) can be described by its __, which is the __.
Why?
 wave function
 mathematical description of the shape of the wave as it vibrates
 all of the wave is positive in sign for a brief instant, then negative

The electron density at any point is given by __, the square fo teh wave function at that point.
Ψ^{2}

Explain the deal with the positive and negatives.
the plus sign and the minus sign of these wave funcitons are not charges. The plus or minus sign is the instantaneous phase of the constantly changing wave function.

As an example, think of a guitar. If we put our hand on one part, on each side, there are still parts moving. We call these vibrating parts __. Why? Which orbital does this resemble?
 out of phase
 when one is upward, the other is downward
 2p

The 2p orbital has __, separated by a __. The two lobes of the p orbital are __ with each other. Whenever the wave function has a __ on one lobe, the other has a __.
 two lobes
 nodal plane
 out of phase
 plus sign
 minus sign

Atomic orbitals can combine and overlap to give more complex __. We can __ and __ their __ to give __ of new orbitals. This process is called the __. The number of new orbitals generated always __.
 standing waves
 add
 subtract
 wave functions
 wave functions
 linear combination of atomic orbitals
 equals the number of starting orbitals

Describe interaction with different atoms and same atoms,
 1) When orbitals on different atoms interact, they produce molecular orbitals (MOs) that lead to bonding (or antibonding) interactions
 2) When orbitals on the same atom interact, they give hybrid atomic orbitals that define the geometry of the bonds.

The stability of a covalent bond results from a large amount of __ in the __, the space between the two nuclei.
In the __, the electrons are close to __, doing what?
 electron density
 bonding region
 bonding region
 both nuclei
 lowering hte overall energy

The bonding electrons also __ of hte nuclei, so the nuclei do not do what?
 mask the positive charges
 repel each other as much as they would otherwise

There is always an __ for the two bonded nuclei. If they are too far apart, their attraction for the bonding electrons is __. If they are too close together, their __. The __ where attraction and repulsion are balanced, which also gives the __ (the __), is the __.
 optimum distance
 diminsihed
 electrostatic repulsion pushes them apart
 internuclear distance
 minimum energy
 strongest bond
 bond length

What happens when wave functions...
add constructively?
add destructively?
 they reinforce each other
 they cancel out where they overlap

When constructive interactions occurs, what happens?
the region where they are in phase has the same sign and they result in a bonding molecular orbital (bonding MO)

When most of the electron density is centered along hte line connecting the nuclei, this type of bond is called the __.
 cylindrically symmetrical bond
 sigma bond

__ are the most common bonds in organic com[ounds. All __ in organic compounds are __, and every __ contains __.
 sigma bonds (σ)
 single bonds
 sigma bonds
 double or triple bond
 one sigma bond

When two orbitals overlap out of phase with each other, an __ results.
For example, if the two 1s wave functions have opposite signs, they will __ where they ___, resulting in a __ (actually a __) separating the two atoms.
 antibonding molecular orbital
 cancel out
 overlap
 node
 nodal plane

What does the presence of a node separating the two nuclei usually indicate?
Symbol for it?
 that the orbital is nonbonding
 σ* to indicate an antibonding (*), cylindrical (σ) molecular orbital

Which has more energy than its atomic orbital, bonding or antibonding?
antibonding

Both bonding and antibonding orbitals exist in all molecules, but the __ are usually __.
 antibonding orbitals (such as σ*)
 vacant in stable molecules

Antibonding molecular orbitals usually __.
participate in reactions

What happens when two p orbitals overlap along the line ebtween the nuclei?
a bonding orbital and an antibonding orbital result

Once again, msot of the electron density is centered along __. This __ is another type of __.
 the line between the nuclei
 linear overlap
 sigma bonding MO

A pi bond results from what?
overlap between two p orbitals oriented perpendicular to the line connecting hte nuclei

These parallel orbitals overlap __, with most of the electron density centered __ the line connecting the nuclei. This overlap is __, not __; so, a pi molecular orbital is not __.
 sideways
 above and below
 parallel
 linear
 cylindrically symmetrical

What does a double bond require?
The first pair of electrons goes into the __, forming a __. The second pair of electrons cannot go into the __ or the __. It goes into a __, with its electron density centered __ the __.
 the presence of four electrons in the bonding region between the nuclei.
 sigma bonding MO
 strong sigma bond
 same orbital or same space
 pi bonding MO
 above and below
 sigma bond

True or False:
Overlap of s and p bonds are more common than hybrid atomic orbitals.

Hybrid aatomic orbitals result from what?
the mixing of orbitals on the same atom

Explain the directionality of s and p orbitals
 s orbitals are nondirectional
 p orbitals are oriented at ninetydegree angles to one anotehr

Bond angles in organic compounds are usually close to __.
109, 120, or 180

A common way of accounting for these bond angles is the __, which is __?
 Valence electron pair reulsion theory (VSEPR theory)
 electron pairs repel each other, and hte bonds nad lone pairs around a central atom generally are separated by the largest possible angles

An angle of __ is the largest possible separation for __; an angle of __ is the largest separation for three pairs; and __ is the largest for two pairs.
 109
 four pairs of elections
 120
 three pairs
 180
 two pairs

Although s and p orbitals have the lowest energies for isolated atoms in space, they are not the best for __. To explain the shapes of common organic molecules, we assume that the s and p orbitals __.
 forming bonds
 combine to form hybrid atomic orbitals that separate the electron pairs more widely in space and place more electron density in the bonding region between the nuclei

Combining a p and s orbital results in what?
an sp hbrid orbal, where the electron density is concentrated toward one side of the atom

The result of hybridization is a pair of __. These hybridized orbitals provide __ in the __ for a __ and for another __.
 directional sp hybrid orbitals pointed in opposite directions
 enhanced electron density
 bonding region
 sigma bond toward the left of the atom
 sigma bond toward the right

sp hybridization results in the __.
linear bonding arrangement

To orient three bonds as far apart as possible, bond angles of __ are required.
120

When an s orbital combines with two p orbitals, the resulting __ are oriented at __ to each other. Thse orbitals are called __ because they are composed of one s and two p orbitals.
 three hybrid orbitals
 120 angles
 sp2 hybrid

The __ is called __, in contrast to the linear geometry associated with sp tbrid orbitals. There remains an __ perpendicular to the plane of the __.
 120 degree arrangement
 trigonal geometry
 unhybridized p orbital (pz)
 three sp2 hybrid orbitals

When four bonds are oriented as far apart as possible, they form a __. This __ can be explained by combining the __. The resulting four orbitals are called __ because they are composed of one s and three p orbitals.
 regular tetrahedron
 tetrahedral arrangement
 s orbital with three p orbitals
 sp3 hybrid orbitals

