Chapter 6 – Chemical Bonding
6-1 Introduction to Chemical Bonding
A. – Intro
1. A chemical bond is a mutual ____________________ _____________________ between the nuclei and
____________________ electrons of different atoms that binds the atoms together.
2. By bonding with each other, atoms decrease in __________________ _________________, thereby
creating more-_______________ arrangements of matter.
B. – Types of Chemical Bonding
1. Ionic bonding is chemical bonding that results from the ___________________ attraction between large
numbers of _________________ and ________________.
a. In purely ionic bonding, atoms completely ___________ ______ electrons to other atoms.
2. Covalent bonding results from the ___________________ of electron ____________ between two atoms.
a. In a purely covalent bond, the shared electrons are “________________” ________________ by
the two bonded atoms
3. The degree to which bonding between atoms of two elements is ______________ or
___________________ can be estimated by calculating the ________________________ in the elements’
______________________________
4. A nonpolar covalent bond is a covalent bond in which the bonding electrons are _________________
_________________ by the bonded atoms, resulting in a ______________________ distribution of
electrical charge.
5. A polar covalent bond is a covalent bond in which the bonded atoms have an __________________
attraction for the shared electrons (and a resulting unbalanced distribution of charge).
6. Complete the following table to summarize this section:
Bond Type
% Ionic Character
Electronegativity
difference
Bonding electrons
are…
Ionic
Greater than ______%
Greater than ______
Transferred
Polar covalent
As high as _______%
As high as _______
Shared unequally
As low as _______%
As low as _______
As high as _______%
As high as _______
As low as _______%
As low as _______
Nonpolar covalent
Shared equally
***On a separate piece of paper, answer Chapter Review Problems #33& 34 from page 196. Attach your
answers to THIS PAGE!
6-2 Covalent Bonding and Molecular Compounds
A. – Intro
1. A molecule is a __________________ group of atoms that are held together by _____________________
bonds.
2. A molecular compound is a chemical compound whose ___________________ units are molecules.
3. A chemical formula indicates the __________________ numbers of atoms of each kind in a chemical
compound by using atomic __________________ and numerical ____________________________.
a. A molecular formula shows the types and numbers of atoms combined in a ________________
molecule of a molecular (covalently bonded) compound.
4. A diatomic molecule is a molecule containing only __________ atoms.
5. Turn to page 243 in your book, and look at Table 8-1. Make a list here of the seven elements that occur in
nature as diatomic molecules:
Element
Symbol
Molecular Formula
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B. – Formation of a Covalent Bond
1. Read this section and understand that the distance between two atoms in a molecule is a “compromise”
between:
a. The repulsion of electron clouds of the two atoms
b. The repulsion of the two nuclei
c. The attraction of the outer electrons of an atom for the nuclei of the approaching atom
They finally “settle” on a distance that minimized the potential energy
C. – Characteristics of the Covalent Bond
1. Bond length is the distance between two bonded atoms at their _______________________ potential
energy
2. Bond energy is the energy required to ________________ a chemical bond and form neutral
____________________ atoms
a. Bond energy is measured in ________________________ per mole (_____/_______)
D. – The Octet Rule
1. The Octet Rule: Chemical compounds tend to form so that each atom, by ___________________,
____________________or ____________________ electrons, has an _________ of electrons in its highest
occupied energy level.
2. Most ___________-group elements tend to form covalent bonds according to the
octet rule. However, there are ________________________, such as
boron______________________.
***On a separate piece of paper, answer Chapter Review Question #35 (parts a and c)
from page 196. Attach your answers to THIS PAGE!
E. – Electron Dot Notation
1. Electron-dot notation is an electron-___________________________ notation in which only the
____________________ electrons of an atom of a particular element are shown, indicated by dots placed
around the element’s ______________________.
2. In general, an element’s number of _____________________ electrons can be determined by adding the
_____________________________ of the element’s noble-gas notation.
***On a separate piece of paper, answer Chapter Review Question #37 from pages 196 and 197. Attach your
answers to THIS PAGE!
F. – Lewis Structures
1. Electron-dot notation can be used to represent _________________________.
a. The pair of dots ___________________ the two symbols represents the ____________________
pair of a covalent bond.
b. An unshared pair, also called a ___________ pair, is a pair of electrons that is not involved in
bonding and that belongs ________________________ to one atom
c. The pair of dots representing a shared pair of electrons in a covalent bond is often replaced by a
___________ ____________.
2. Lewis Structures are formulas in which atomic symbols represent _______________ and __________shell electrons, dot-pairs or ______________ between two atomic symbols represent electron
____________ in covalent bonds, and dots adjacent to only one atomic symbol represent
___________________ electrons.
3. A structural formula indicates the ___________, number, ___________________________, and bonds
but not the ________________________ pairs of electrons in a molecule.
4. A single bond is a covalent bond produced by the ____________________ of _______ pair of electrons
between two atoms.
***Do the separate worksheet on Writing Lewis Structures. Follow the examples in your textbook. Attach the
completed worksheet to this page.
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G. – Multiple Covalent Bonds
1. Atoms of some elements, especially _________________, _________________ and ________________,
can share more than __________ electron pair.
2. A double bond is a covalent bond produced by the sharing of ________ pairs of electrons between
_______ atoms. It is either shown by two _________-by-__________ pairs of dots, or by two
_________________ dashes.
3. A triple bond is a covalent bond produced by the sharing of ___________ pairs of electrons between
________ atoms.
4. Double and triple bonds are referred to as ______________________ bonds, or __________________
covalent bonds.
a. Double bonds in general have higher _____________ ________________ and are
_________________ than single bonds.
b. Triple bonds are even ______________________ and ___________________
5. In writing Lewis structures for molecules that contain _________________, _________________ and
________________, one must remember that multiple bonds are possible.
H. – Resonance Structures
1. Some molecules and ions cannot be represented __________________________ by a ___________ Lewis
structure. One such molecule is ozone, ______.
2. Chemists once ________________________ that ozone split its time existing as one of these _______
structures, constantly “________________________” from one to the other. Experiments revealed that the
oxygen-oxygen bonds in ozone are __________________________. Scientists now say that ozone has a
single structure that is the _____________________ of these two structures. Together, the structures are
referred to as resonance structures or resonance _____________________.
3. Resonance refers to bonding in molecules or ions that cannot be ___________________ represented by a
single structure.
I. – Covalent-Network Bonding
Save it for Chapter 11…
6-3 Ionic Bonding and Ionic Compounds
A. – Intro
1. An ionic compound is composed of positive and negative ions that are combined so that the numbers of
positive and negative _______________ are _______________. Most ionic compounds exist as
_________________________ solids. It is a ______________-dimensional network of positive and
negative ions mutually _____________________ to one another.
2. The chemical formula of an ionic compound shows the ____________ of the ions present in a sample of
__________ _____________.
3. A formula unit is the _______________________ collection of atoms from which an ionic compound’s
formula can be established. The ratio of ions in a formula unit depends on the ____________________ of
the ions combined.
B. – Formation of Ionic Compounds
1. The transfer of an electron from the _______________ atom to the _________________ atom transforms
each atom into an ion with a ___________-_______ configuration.
2. In the combination of calcium with fluorine, _______ fluorine atoms are needed to accept the ______
_____________________ electrons given up by one calcium atom.
3. Teacher's condensed version: Much like covalent bonding, the formation of crystals involves a balance
between the forces of attraction and repulsion. The formation of ionic crystals is driven by the natural
tendency toward lower energy (greater stability).
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4. To compare ___________ strengths in ionic compounds, chemists compare the amounts of energy
___________________ (never absorbed!) when separated ions in a __________ come together to form a
crystalline solid. Lattice energy is the energy ______________when one mole of an ionic crystalline
compound is formed from ________________ions.
5. The negative energy values indicate that energy is ________________ when crystals are formed.
C. - A Comparison of Ionic and Molecular Compounds
1. The force that holds ions together in ionic compounds is a __________ ______________ overall attraction
between positive and negative charges.
2. In a molecular compound, the covalent bonds of the atoms making up each ____________________ are
also ________________. But the forces of attraction ________________ ______________________ are
much ____________________ than the forces of ionic bonding.
3. Because the forces of attraction between individual _____________________are not very ____________,
many molecular compounds __________ at ________ temperatures.
4. Because of the ____________ forces that hold ions together, ionic compounds generally have __________
melting and boiling points than do ___________________ ____________________.
D. - Polyatomic Ions
1. A polyatomic ion is a _______________ group of ____________________ bonded atoms. The charge of
a polyatomic ion results from an ______________ of _____________________ (________________
charge) or a ____________________ of ___________________ (________________ charge).
You do not have to memorize ions and their charges in this chapter. You WILL have to memorize them in
Chapter 7.
6-4 Metallic Bonding
A. - Intro
1. Chemical bonding is __________________ in metals than it is in other compounds.
2. The excellent electrical conductivity of metals is due to the highly __________________ valence electrons
of the atoms that make up a metal.
B. - The Metallic-Bond Model
1. Within a metal, the vacant ________________ in the atoms' outer energy levels ________________. This
___________________ of orbitals allows the outer electrons of the atoms to ___________ ____________
throughout the entire metal. The electrons are _____________________, which means that they do not
belong to any _________ ____________. These _______________ electrons form a _______ of electrons
around the metal atoms, which are packed together in a crystal __________________.
2. Metallic bonding is the chemical bonding that results from the ___________________ between metal
atoms and the surrounding _________ of electrons.
3. Metallic properties is a review of information covered in Chapter 1.
4. Metallic bond strength varies with the ________________ charge of the metal atoms and the number of
electrons in the metal's _________________ _________. Heat of vaporization, the amount of heat
required to vaporize a metal, is a measure of the _________________ of the bonds that hold the metal
together.
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6-5 Molecular Geometry
A. - Intro
1. The properties of molecules depend not only on the bonding of atoms, but also on ____________________
____________________ -- the ___________-dimensional arrangement of a molecule's atoms in space.
The _______________ of each bond, along with the ____________________ of the molecule, determines
molecular polarity, or the ______________ distribution of molecular _______________.
2. Molecular polarity strongly influences the _________________ that act between molecules in liquids and
solids.
B. - VSEPR Theory
1. VSEPR stands for "________________-shell, _______________-pair ____________________."
2. VSEPR states that ____________________ between the sets of ___________________-level electrons
surrounding an atom causes these sets to be oriented as ________ ____________ as _______________.
3. VSEPR theory states that lone pairs ______________ space around the central atom, but the actual shape
of the molecule is determined by the positions of the ___________ only. Unshared electron pairs
_______________ electrons more ________________ than do __________________ electron pairs.
***On a separate piece of paper, answer Section Review Question #2 from page 193. Attach your answer to
THIS PAGE!
C. - Hybridization
1. Hybridization is the _____________________ of two or more atomic orbitals of ___________________
energies on the same atom to produce new orbitals of _____________ energies.
2. Write the expected valence orbital notation for carbon:
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3. Write the sp hybridized orbital notation for carbon:
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The sp orbitals all have the same __________________, which is greater than that of the _____ orbital but
less than that of the _____ orbitals.
D. - Intermolecular Forces
1. Intermolecular forces are the forces of ____________________ between molecules.
2. The strongest intermolecular forces exist between _______________ molecules. They act as tiny
_____________ because of their uneven ______________ distribution.
a. A dipole is created by equal but ___________________ charges that are separated by a
___________ distance.
b. The direction of a dipole is from the dipole's __________________pole to its __________________
pole.
c. The negative region in one polar molecule attracts the _____________________ region in
_____________________ molecules.
d. The forces of attraction between polar molecules are known as ____________-___________
forces.
e. A polar molecule can _______________ a dipole in a ___________________ molecule by
temporarily ___________________ its electrons
3. Hydrogen bonding is a particularly ______________ type of dipole-dipole force. It is the intermolecular
force in which a hydrogen atom that is bonded to a highly _________________________ atom is attracted
to an unshared pair of electrons of an __________________________ atom in a _____________ molecule.
4. London dispersion forces are intermolecular attractions resulting from the constant ________________ of
electrons and the creation of _________________________ _________________.
a. London forces exist between ________ molecules but are the _________ intermolecular forces
acting among __________-gas atoms, nonpolar molecules and ______________ polar molecules.
b. London forces increase with increasing _____________ or _______________ mass.
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