1 Ionic Bonds (1)

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Ionic Bonds
Chemistry
Mrs. Coyle
Part A:
 Ions
 Lewis Dot Structure
 Stable Octet (or Duet)
The Periodic Table and Atomic Radius
Valence Electrons
 Valence electrons are the electrons in the
highest occupied energy level of the atom.
 Valence electrons are the only electrons
generally involved in bond formation.
Electron Configuration of Sodium
 1s2 2s2 2p6 3s1
 Which is the valence electron for Na?
 Answer: 1s2 2s2 2p6 3s1
Na , 11 e
Na + , 10e
A Positive Ion (Cation):
 An atom that has lost one or more electrons.
 + charge
Electron Dot Structure or
Lewis Dot Diagram
A notation showing the valence electrons
surrounding the atomic symbol.
Elements within the same group have
the same electron-dot structure.
A Negative Ion (Anion)
 An atom that has gained one or more
electrons.
 Negatively (-) charged.
Chlorine Atom  Chlorine Ion
Check your Neighbor
When Na, (Z= 11) loses its valence
electron, what element does its
configuration look like ?
a.
b.
c.
d.
Neon
Potassium
Beryllium
Sodium
Check your Neighbor
When Na, (Z= 11) loses its valence
electron, what element does its
configuration look like ?
a.
b.
c.
d.
Neon
Potassium
Beryllium
Sodium
A Stable Octet
When the valence shell is full, the
atom is stable, less likely to react.
Example: Noble (Inert Gases)
Kr
Note
 Atoms tend to react in a way that would lead
them to have a stable octet.
Part B:
 Equations for Formation of Ions and Naming
Ions
 Ionic Bonds and Ionic Compounds
Equations for the Formation of Cations
.
H
 H+
+ e-
.
Li
 Li+
+ e-
Mg:
 Mg2+
+ 2e-
Equations for the Formation of Anions
.
:F:
..
..
+ e-  : F -
..
:
Naming cations (+).
 Use the name of the metal.
 Example: Na+
 Sodium ion.
Naming Anions(-)
 Use the name of the nonmetal with the
ending –ide.
 Example: F Fluoride
Ionic Compounds
 Are made up of:


a metal and a nonmetal ion.
polyatomic ions.
Naming Ionic Compounds,
a First Look
 Example:

NaF
Sodium Fluoride
Example:
 Which of the following compounds are ionic?
1.
2.
3.
4.
5.
NaCl
CO2
CO
KF
KNO3
Some Common Ions
Bonding
 Elements that do not have a complete octet,
tend to react.
 When the elements react bonds are formed.
Types of Bonds
 Ionic
 Metallic
 Covalent
Ionic Bonds
 Bonds that are formed by transfer of
electrons from one element to the other.
 Each element (now an ion) will have a
complete octet after the transfer of electrons.
The Ionic Bond
• The electrical force of attraction between
oppositely charged ions.
Na+
F−
Example:
Formation of Lithium Fluoride
.
.
Li
+
:F:
..
..

Li+
:
F-
..
:
Is an Ionic Compound Electrically
Neutral or Charged?
Movie Clip
 http://www.youtube.com/watch?v=Kj3o0XvhV
qQ&NR=1
Chemical Formula
 A representation of the kinds and number of
atoms in a substance.
Formula Unit
 A chemical formula that shows the
lowest whole number ratio of the
atoms (ions) in an ionic compound.
 Example: KCl,
Mg Cl2
The formula unit is used because ionic
compounds have a lattice arrangement
of ions. Ex: NaCl
 Which ball
represents
the Na?
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