Chem: Chapter 4
Is the three-dimensional arrangement of atoms in a molecule
Molecular structure
The structure around a given atom is determined principally by
minimizing electron pair repulsions
Valence shell electron-pair repulsion (VSEPR) model
When there are four pairs of electrons around an atom, they
take up a
tetrahedral structure
In the presence of a lone pair, the molecular structure is a
trigonal pyramid
The arrangement of electron pairs is ........, but the
arrangement of ........ is not
tetrahedral & atoms
Bonding pairs are shared between two .....
nuclei
Lone pairs center around just ....... ......., and both electrons
choose that nucleus
one nucleus
When there are five electron pairs, the structure that
produces minimal repulsion is a ...... .......
trigonal bipyramid
The best arrangement for six pairs of electrons around a
given atom is the ...... ......
octahedral structure
While using the VSEPR model, a ..... ..... must be
considered as one effective pair
double bond
The ..... ...... acts as one center of electron density that
repels other electron pairs
double bond
A molecule that has a center of positive charge and a center
of negative charge is said to be ...... or to possess dipole
moment
dipolar
.... - Most electron-rich region
Red
..... - Most electron-poor region
Blue
Any ...... ...... with polar bonds will exhibit dipole
moments
diatomic molecule
It refers to the mixing of the native atomic orbitals to form
special orbitals for bonding
Hybridization
Electron pair is shared in an area centered on a line running
between the atoms
Sigma bond
Forms double and triple bonds by sharing electron pair(s) in the space above and below the σ bond using the unhybridized p orbitals
Pi bond
A .... ... ... is lower in energy than the atomic
orbitals from which it is composed
Bonding molecular orbital
An ..... ..... ..... is higher in energy than the
atomic orbitals from which it is composed
Antibonding molecular orbital
The number of .... .... will always be equal to the number of
atomic orbitals used to construct them
Molecular Orbitals
...... causes a substance to be attracted into the
inducing magnetic field
Associated with ...... electrons
Paramagnetism & unpaired
.... causes a substance to be repelled from the
inducing magnetic field
Associated with .... electrons
Diamagnetism & Paired
bond can be described as being localized
Sigma
bonding can be treated as being delocalized
Pi