Transcript PowerPoint Ionic bonding rev

IONIC COMPOUNDS
REVIEW OF ATOMIC STRUCTURE

The structure of the atom
Neutrons + Protons
are in the nucleus
Electrons in orbits
around the nucleus
Protons = Positive Charge
Electrons = Negative Charge
Neutrons = Zero Charge
IONIC COMPOUNDS – The Octet Rule

Atoms in groups 1 – 13 (metals) will lose
electrons in order to achieve a full outer shell


Atoms in groups 15 – 17 (nonmetals) will gain
electrons in order to achieve a full valence shell



They become cations (positive)
They become anions (negative)
Combining Capacity: the number of electrons an
atom needs to gain or lose to achieve a full outer
shell
The positive and negative ions attract to form an
ionic bond
IONIC COMPOUNDS – Ionic Charges of
the Elements
+1
+2
+3
-3 -2 -1
IONIC COMPOUNDS – The Formation
of an Ionic Bond
IONIC COMPOUNDS – The Formation
of an Ionic Bond


Ionic compounds are formed when a metal (M) is
bonded to a nonmetal (N)
In general:
M
N
MN
M
N
MN
IONIC COMPOUNDS – Writing
Chemical Formulas

Rules
Assign ionic charges to each atom
 Apply the criss-cross rule (ONLY the numbers travel,
NOT the sign)



Reduce the subscripts by dividing by the highest common
factor
Write your chemical formula
IONIC COMPOUNDS – Writing
Chemical Formulas

Example 1: sodium and chlorine
Na
+1
Na
1
Cl
Cl
NaCl
-1
1
IONIC COMPOUNDS – Writing
Chemical Formulas

Example 2: calcium and chlorine
Ca
Ca
+2
1
Cl
Cl
CaCl
2
-1
2
IONIC COMPOUNDS – Writing
Chemical Formulas

Example 3: lithium and oxygen
Li
Li
O
+1
O
2
Li O
2
-2
1
IONIC COMPOUNDS – Writing
Chemical Formulas

Example 4: magnesium and oxygen
Remember
to find
+2
-2
the HIGHEST
COMMON
FACTOR
Mg
Mg
O
O
2
Mg O
2
2
2
IONIC COMPOUNDS - Naming

Rules…
1.
2.

Write the metal’s name first
Write the nonmetal’s name second (change the
ending to “-ide”)
For example: NaCl = sodium chloride
IONIC COMPOUNDS - Naming
Chemical Formula
Chemical Name

CaCl2

Calcium chloride

Li2O

Lithium oxide

MgO

Magnesium oxide
IONIC COMPOUNDS – Multivalent
Metals
Some metals can have different combining
capacities in different compounds
 For example:

Copper (Cu) = 1, 2
 Iron (Fe) = 2, 3
 Lead (Pb) = 2, 4
 Tin (Sn) = 2, 4


These numbers are
written as Roman
Numerals (i.e. I, II,
III, IV, V)
In these cases, the combining capacity must be
specified using Roman Numerals
IONIC COMPOUNDS – Multivalent
Metals

Iron(II) chloride
Fe
+2
Fe
1

Iron(III) chloride
ClcombiningFe
-1
+3
Iron has two
capacities. Iron can
have a +2 or +3
charge.
Cl
2
FeCl
2
Fe
1
Cl
Cl
-1
3
FeCl
3
HOMEWORK

“IONIC COMPOUNDS” Worksheet