Ionic bonding

1. HAPPY HALLOWEEN! �
• Date: October 31st
2018
• Topic: Imagine you are a scientist working on the cure
to the zombie apocalypse. You and your team finally
develop a cure, but now you must transport the it from
your lab to the Center for Disease Control for mass
distribution. The problem: zombies are already walking
the earth.
• What do you do? How do you get the cure in the right
hands before it’s too late? Do you survive? Write a short
journal entry of your plan or zombie encounter.

3. LEARNING CHECK – COUNTING
State the number of protons, neutrons, and
electrons in each of these ions.
K+
O -2
Ca +2
#p+
______ ______ _______
#no
______ ______ _______
#e-
______ ______ _______
19
20
18
8
8
10
20
20
18

4. ONE LAST LEARNING CHECK
Write the nuclear symbol form for the following
atoms or ions:
A. 4 p+
, 5 n, 2 e-
___________
B. 17p+
, 18n, 17e-
___________
C. 13p+,
14n, 10e- ___________
Al3+
Cl
Be2+

5. IONIC BONDING

6. IONIC BOND
A bond formed between two oppositely charged ions
by the transfer of electrons from one element to the
other.
OPPOSITES ATTRACT!
Each element (now an ion) will have a complete octet
after the transfer of electrons.
Forces between the ions are very strong

7. NOBLE GAS STABILITY
Noble gases are usually unreactive
This is because they have full valence shells
An element with a full valence shell is a happy
element 
For two atoms to join together atoms must gain, lose or
share electrons
Elements with full valence shells do not easily gain or
lose electrons

8. NOBLE GAS STABILITY
Atoms want to gain stability
Atoms will try to gain or lose electrons to have a full
valence shell
Metals try to lose electrons
Non-Metals try to gain electrons

9. FORMATION OF IONS FROM METALS
Ionic compounds result when metals react with
nonmetals
Metals lose electrons to match the number of
valence electrons of their nearest noble gas
Positive ions form when the number of electrons
are less than the number of protons
Group 1A metals → ion 1+
Group 2A metals → ion 2+
Group 3A metals → ion 3+

10. FORMATION OF IONS FROM
NONMETALS
In ionic compounds, nonmetals in groups 5A, 6A, and 7A
gain electrons from metals
Nonmetals add electrons to achieve the octet arrangement
Nonmetal ionic charge:
3-, 2-, or 1-

11. Recall Lewis dot structures from last class:

13. BINARY IONIC COMPOUNDS
• Binary compounds are those that contain only two
different elements.
• The names for binary ionic compounds containing a
metal that forms only one type of ion have the
following form:
Name of Cation + Base Name of Anion + ide

14. NAMING CATIONS (+)
Use the name of the metal.
Example: Na+ =
Sodium ion

15. NAMING ANIONS(-)
Use the name of the nonmetal with the ending –ide.
Example: Cl-
= Chloride

16. SOME COMMON IONS

17. LEARNING CHECK
Which of the following compounds are ionic?
1. NaF
2. CO2
3. CO
4. KF

18. NAMING IONIC COMPOUNDS,
A FIRST LOOK
Example: NaCl
Sodium Chloride

19. Sodium chloride is an ionic compound formed by the reaction
between the metal sodium and the non-metal chlorine.
 Sodium has 1 electron in its
outer shell.
 Chlorine has 7 electrons in its
outer shell.
2.8.7 [2.8.8]-
+
Cl Cl
-
2.8.1 [2.8]+
Na Na
o By losing this electron, it
has a filled outer shell and
forms a positive ion.
o By gaining an electron from
sodium, it has a filled outer
shell and forms a negative
ion.

20. WHAT IS THE RATIO OF IONS IN
SODIUM OXIDE?
Na
Na
O O2-
Na+
Na+
1 electron
from each
Na atom
Sodium needs to lose 1 electron to form a sodium ion but oxygen
must gain 2 electrons to form an oxide ion
Two sodium atoms are required for each oxygen atom and so
the ratio of sodium ions to oxide ions is 2:1
From this ratio, the formula of sodium oxide is Na2O

21. PRACTICE
• Name these compounds:
• CaO
• Al2O3
• KF
• MgCl2
• Li3N

22. BINARY IONIC COMPOUNDS
• If the cation could have more than one charge, then
the charge must be specified in the metal’s name.
• We specify the charge with a Roman numeral (in
parentheses) following the name of the metal.
• For example, we distinguish between Cu+
and Cu2+
by
writing a (I) to indicate the 1+ ion or a (II) to indicate
the 2+ ion:
• Cu+
 Copper(I)
• Cu2+
 Copper(II)

23. BINARY IONIC
COMPOUNDS
• These compounds are named using the following form:
Name of
Cation
Base Name of
Anion + ide
(charge of metal in
roman numerals)
+ +

24. BINARY IONIC
COMPOUNDS
• What is the charge of iron in FeCl3?
• +3
• What is the name for FeCl3?
• Iron (III) Chloride

25. HOW TO WRITE THE FORMULA
OF AN IONIC COMPOUND

26. EXAMPLE
What is the formula of aluminium bromide?
Al
Br
Al3+
Br
Br
Br
-
Br
-
Br
-
1 electron
for each
bromine
atom

27. TRY THIS
• What is the formula for magnesium bromide

28. POLYATOMIC IONS
• Polyatomic Ion: An ion (either positively or negatively
charged) composed of two or more atoms.
• Examples:
HCO3
2-
Bicarbonate Ion
PO4
3-
Phosphate Ion
NH4
+
Ammonium Ion
NO3
-
Nitrate Ion

29. POLYATOMIC IONIC
COMPOUNDS
• Ionic compounds containing polyatomic ions are
named using the same procedure we apply to other
ionic compounds, except that we use the name of the
polyatomic ion whenever it occurs.
• For example, we name KNO3 using its cation, K+
,
potassium, and its polyatomic anion, NO3
-
, nitrate.
• KNO3 potassium nitrate

30. PRACTICE
• Fe(OH)2
• NH4NO3

31. PRACTICE
• Write the formula for the following compounds:
• barium nitrate
• ammonium iodide
• iron (III) hydroxide