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Chapter 8
Ionic Compounds
Chemical Bonds
 Chemical
bonds form so
elements can attain a stable
electron structure
 8 outer electrons is the most
stable structure
 Atoms will gain/lose electrons
to reach either 0 or 8
Chemical Bonds
 Pseudo
Noble Gas – When an
ion forms that results in full s
& p sub-levels (may be some d
or f electrons still hanging on)
Cations (Positive Ions)
 Results
from an atom losing
electrons to increase their
stability
 Charge is equal to the number
of electrons lost
 Sodium loses 1 electron 
charge = 1+
 All metals
Anions (Negative Ions)
Formed when elements gain
electrons in bonding
2. To name add –ide to element
name
1. Sulfur = sulfide
3. Charge = number of electrons
gained
1. Fluorine gains 1  charge = 11.
Assignment
Make a list of 10 elements
2. Exchange with a partner and
give:
1. Electron configuration
2. Type of ion formed
(cation/anion)
3. Electron dot diagram
4. Charge of the ion formed
1.
Chapter 8.2
Ionic Compounds
Ionic Bond
 Electrostatic
force holds
oppositely charged particles
together
 Formed between metals and
non-metals
Binary Compounds
 Compounds
that contain
only two elements
 Metallic
cation and
nonmetallic anion
 Number
of electrons lost by
the cation must equal the
number of electrons gained
by the anion
Binary Compounds
1. Na
+ Cl  NaCl
2+
12. Mg
+ Cl  MgCl2
1+
23. K
+ S  K2S
1+
1-
Properties of Ionic
Compounds
During the formation of ionic
compounds the positive and
negative ions are arranged in
repeating patterns (crystal
lattice) that determine the
properties of the compound
as a whole
Crystal Lattice
3-d geometric
arrangement of
particles
 Vary in shape
due to the size
and number of
ions bonded
Crystal Lattice
Melting and Boiling points and
hardness are determined by the
crystal lattice
 Lattice energy is a result of the
electrostatic attractions
between oppositely charged
ions
 There is an inverse relationship
between lattice energy and
interionic distance

Electrolyte


Ionic solution that conducts
current
Solid ionic compounds will
not conduct since ions are
not free to move
Energy Changes During
Bond Formation
Exothermic Reaction – Energy is
released during a reaction
1. Formation of ionic compounds
from positive and negative ions
is always exothermic
2. Endothermic Reaction – Energy
is absorbed during a reaction
1.
Assignment





What is a chemical bond?
Why do ions form?
What family of elements is
relatively unreactive and
why?
Describe the formation of
both positive and negative
ions
What would be the ionic
charge of each of the
following:




N
S
Ba
Li





What is an ionic bond?
How does an ionic bond form
List 3 physical properties of an
ionic bond
Describe the arrangement of
ions in a crystal lattice
What is lattice energy and how
is it involved in an ionic bond?
Explain the formation of the
ionic compound for each of the
following pairs:

Na & N; Li & O; Sr & F; AL & S
Chapter 8.3
Writing Formulas and
Naming Ionic
Compounds
Rules for Writing Formulas
for Ionic Compounds
1.
2.
3.
Formula represents the
simplest ratio of ions in a
compound
Overall charge of the
compound must equal 0
Cation is always listed first
Oxidation Numbers
(determining charge)
Monatomic Ions – Ions
composed of one element
1. Oxidation number is
dependent on location on the
periodic table
2. If a particular oxidation is
not specified use the bold
oxidation number
Oxidation Numbers
(determining charge)
Polyatomic Ions – Ions composed
of more than one element, but
acting as a single cation or anion
1. Table 8-6 on page 224 must be
copied on your periodic table
2. Charge on table is for the entire
ion
3. NEVER change subscripts in a
polyatomic ion

Assignment:
Write the correct formula for  How do you determine the
correct subscripts in a
the following pairs of ions
chemical formula?
 Potassium and iodide
 What subscripts would most
 Magnesium and chloride
likely be used if the following
 Aluminum and bromide
substances formed an ionic
 Cesium and nitride
compound?
 Barium and sulfide



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Sodium and nitrate
Calcium and chlorate
Aluminum and carbonate
Potassium and chromate
Magnesium and carbonate





An alkali metal and a halogen
An alkali metal and a nonmetal
from group 16
An alkaline earth metal and a
halogen
An alkaline earth metal and a
nonmetal from group 16
A metal from group 3 and a
halogen
Naming Ionic Compounds
Oxyanions – Polyatomic ion with
oxygen
1. Ion with most oxygen atoms =
root of the nonmetal plus –ate
2. Ion with fewer oxygen atoms =
root of nonmetal plus -ite
Naming Ionic Compounds
(Halogens)
Most O = per- root –ate
1. ClO4 = perchlorate
2. 1 fewer = root –ate
1. ClO3 = chlorate
3. 2 fewer = root –ite
1. ClO2 = chlorite
4. 3 fewer = hypo- root –ite
1.
1.
ClO = hypochlorite
Binomial Nomenclature
1.
2.
3.
Name cation first, anion last
1. Cation – just use the name
2. Anion – root of the name plus –ide
If compound contains a polyatomic
ion just name the ion
Transition Metals must include a
roman numeral to indicate which
oxidation state is used
Assignment:



What is the difference
between a monatomic ion • Name the following
compounds:
and a polyatomic ion
• NaBr
How are the metals, non• CaCl2
• KOH
metals and polyatomic ions
• CU(NO3)2
named in an ionic
• Ag2CrO4
compound?
What is an oxyanion and
how is it named?
Complete the table by providing the correct
formula for each combination:
Oxide Chloride Sulfate
Potassium
Barium
Aluminum
Ammonium
Phosphate
Chapter 8.4
Metallic Bonds/Alloys
Metallic Bonding
 Formation
of a lattice
structure created when a
group of atoms are crowded
together and the outer-level
orbitals overlap
 Electrons are not shared, nor
are they gained or lost
Metallic Bonding
Electron Sea Model
 Electrons overlap creating an
artificial stability
 Overlap allows electrons to
move freely from one atom to
another
Delocalized Electrons
 Free
to move between atoms
 Delocaliztion causes:
 High melting and boiling points
 Malleability and ductility
 Good conductivity
 Increase in hardness/strength
with an increase in the number
of electrons
Alloys
 Mixture
of metallic elements
 Produced to attain properties
not associated with any one
metal
Steel = Fe & C or Ni
Brass = Cu & Zn
Gold Jewelry = Au & Cu
Types of Alloys
1.
Substitutional – Atoms of one
element replace the other due to
similarities in size (most
common)
1.
2.
2.
Sterling silver (Ag&Cu)
Pewter (Sn, Sb & Pb)
Interstitial – Formed when gaps
between atoms are filled with
smaller atoms
Assignment:

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What is a metallic bond?
Explain how the conductivity of electricity and high melting
points of metals are explained by metallic bonding.
What is an alloy?
How does a substitutional alloy differ from an interstitial alloy?
In the lab, how could you determine if a solid has an ionic
bond or a metallic bond?