Chapter 7
Ionic and Metallic Bonding
Mr. Samaniego
Lawndale High School
Section 7.1 - Ions
•When Mendeleev arranged his periodic table
according to properties, he didn’t know that it was
also due to the number of bonding electrons
•The reason that certain elements were grouped
together was because they have the same
number of valence electrons
• Valence Electrons – electrons in the highest
occupied energy level of an atom
• To find the valence electrons in an atom of the
representative element, simply look at the group
number
He
2 e-
Determine the Valence electrons
in each of these elements
1.
2.
3.
4.
5.
K
P
C
O
N
6. Be
7. Li
8. He
9. Ne
10. B
Electron Dot Structure
A
diagram that shows valence electrons
as dots around the element symbol
PRACTICE
1. K
6. Be
2. P
7. Li
3. C
8. He
4. O
9. Ne
5. N
10. B
Valence Electrons

The reason that valence electrons are so
important is that they are the only
electrons involved in bonding
Octet Rule
 Remember
that all atoms want to be like
the noble gases because their s and p
orbitals are completely filled, which
makes them unreactive and stable
 The
Octet Rule states that all atoms
want 8 electrons in their valence
shells, just like the noble gases
(except He)
Satisfying the Octet Rule
 In
forming compounds, atoms want to
achieve a noble gas configuration

In order for atoms to combine together to
obtain 8 valence electrons, they transfer
electrons (either gain or lose electrons)
Some atoms will gain electrons,
while other atoms will lose electrons
Filling Order: 1s 2s 2p 3s 3p 4s 3d 4p

Draw the orbital diagram for Sodium

Draw the orbital diagram for Magnesium

Draw the orbital diagram for Fluorine

Draw the orbital diagram for Oxygen
Cation versus Anion

Remember that atoms are electrically
neutral because they have the same
number of protons and electrons
How are electrons transferred?
 Metals
lose valence electrons
 Nonmetals
gain valence electrons
Bonding

Once an atom has a stable octet, it is
happy and does not want to react anymore
Atoms without stable octets are
sad and want to react with other
atoms to achieve a stable octet


Why don’t noble gases want to form bonds?
Why do atoms form bonds?
1. To have a full octet
2. To be more stable
3. To be less reactive
How do atoms become more
stable and less reactive?
By having completely filled s and p
orbitals just like the noble gases
Charges on the Periodic Table
Practice

What are the charges on the following elements?
1. Calcium
2. Oxygen
3. Chlorine
4. Hydrogen
5. Cesium
6. Helium
7. Krypton
8. Aluminum
Section 7.2 – Ionic Bonds

Ionic Compounds are METAL cations and
NONMETAL anions held together by
electrostatic forces

Ionic compounds are formed through
transferring or exchanging electrons
Example…

Sodium Chloride (Salt, NaCl) is an
example of an ionic compound
Practice

Which of the following are ionic compounds?
1.
2.
3.
4.
5.
6.
7.
8.
LiCl
NaS
C2H4
MgBr2
H2O
SiC
Rb3P
CsI
Ionic Charges
 Although
they are composed of
positive and negative charges,
ionic compounds are overall
electrically neutral because their
charges will cancel out
 For
example…
Na+1 will bond with Cl-1
 Mg2+ will bond with O2 Al3+ will bond with N3 Two K+1 can also bond with One S2
Writing Chemical Formulas
3+
Al
3+
Al
2S
2S
2S
Al2S3
The numbers on top are the charges,
while the numbers on the bottom tell
how many atoms there are
Practice
Write as many compounds as you can
with the following ions. Remember
that the overall charge must be zero.
There are 9 possible.
Li+1 Ca2+ Al3+ N3-
S2- Cl-1
Salt

Salt crystals are repeating patterns of
positive and negative ions held together by
electrostatic attraction
Ionic Bonding

When cations and anions transfer
electrons, a SALT is formed

Draw the electron dot structure for the
following atoms
 Li and Br
 Mg and O
 Two K and One S
 One Sr and Two F
SALTS
When cations and anions form bonds
with each other they are called SALTS

Example:
Li+
Li
1s
LiF
2p
F
F1s
2p
Practice
Show how the following compounds bond
with the use of orbital diagrams
1. NaF
2. MgO
3. Li2S
4. CaCl2
5. AlN
Properties of Ionic Compounds
Crystalline Solid at Room Temperature
 High Melting Points
 Can conduct an electric current when
melted or dissolved in water

Section 7.3 – Bonding in Metals
Metal
atoms are
arranged in very
compact and
orderly patterns
Metallic Bond

A Metallic Bond is a bond between metal
cations surrounded by a sea of electrons
Metallic Bond
The attraction
of the free
floating
valence
electrons
holds them
together
Crystalline Structure of Metals
(Page 202)
Properties of Metals
1. Good
Conductors of
electrical current
2. Ductile (ability to
be stretched)
3. Malleable
(ability to be
shaped)
Alloys
 Very
few of the metal objects you use
everyday are pure metals
 Alloys
are a mixture of two or more
elements, at least one being a metal
 Alloys
are important because the
combination of metals are stronger
than the single metal by itself
Examples of Alloy Combinations
Brass – copper and zinc
 Sterling Silver – silver and copper
 Bronze – copper and tin
 Steel – iron, carbon, boron, chromium,
manganese, molybdenum, nickel,
tungsten, vanadium
 Stainless Steel – iron, chromium, carbon,
nickel
 Cast Iron – iron and carbon

Homework
Chapter 7 Assessment
#’s 30-44, 48, 53, 55, 56, 58, 59, 60, 62, 63,
64, 65, 72, 73, 87, 88, 90, 92, 93, 94, 95