Ions and Ionic Compounds
QUALITATIVE ANALYSIS
There are four methods for identifying matter:
(1) Thermal Emission Spectroscopy
(2) Light Spectroscopy
(3) Flame Tests
(4) Conductivity
Electrolyte Example:
Non-Electrolyte –
Example:
LEWIS SYMBOLS
 A diagram that uses the
and dots to represent only
 Electrons are drawn in
around the symbol, and are then paired
 The number of valence electrons can be determined by looking at the group number
Examples Problem: Draw a Lewis Structure for the following Elements.
(A) Carbon
(B) Fluorine
(C) Phophorous
(D) Calcium
(E) Argon
FORMING IONS
 When an atom becomes an ion, it wants to become
.
 These atoms want to have their valence shell completely filled like the
 The
(8 electrons full) is a rule that is followed when atoms combine with
other atoms to have a stable electron arrangement
 Atoms can become stable by
,
(when there are <4 e-),
(when there are >4e-)
CATIONS
 Metals on the (left side and middle
of the periodic table) generally tend
to
 These elements tend to have a few
electrons in their valence shell.
 When they lose electrons, they
form
ions
called
.
ANIONS
 Non-metals (on the right side of
the periodic table) generally tend
to
 These elements tend to have
more than 4 electrons in their
valence shell
 When they gain electrons, they
form
ions called
.
 The names of non- metal anions end with
(Ex. Chlorine = Chloride Ion)
.
Example Problem:
Draw a Lewis Structure for the Following Ions
(A) Aluminum Ion
(B) Fluoride Ion
(C) Nitride Ion
(D) Calcium Ion
(E) Sulfide Ion
(F) Lithium Ion
IONIC BOND
 Ionic bonds form between a
and a
.
 Metals lose their electrons and become cations (positive ions)
 Non-metals gain their electrons and become anions (negative ions)
 The positive and negative charges (opposite)
to form an ionic bond
Example Problem: Using Lewis Structures, show how an ionic bond is formed between the
following atoms.
(A) lithium and sulfur
(B) magnesium and oxygen
(C) calcium and nitrogen
IONIC COMPOUNDS
 An
is formed from a combination of
cations and anions arranged in a 3-D structure.
 Ionic crystal are arranged using
which are the
smallest repeating units in the ionic crystal. For sodium chloride Na and
Cl are in a 1:1 ratio.
WHY DO IONIC COMPOUNDS CONDUCT ELECTRICITY?
 When ionic compounds are dissolved in water, the
separate from the
.
The separation is called
.
 The movement of ions causes
to flow
through the solution.