1. Ions
Atoms that lose electrons (negative) have more positive charge than negative charge so they are positive ions.
Atoms that gain electrons (negative) have more negative charge than positive charge so they are negative ions.
When there are only nonmetal atoms present, they all need additional electrons, so they share electrons amongst themselves.

2. Ionic Compounds
Positive and negative ions will bond to each other because of their electrostatic attraction.
This attraction is called an ionic bond.
Metals and nonmetals always bond together using ionic bonds.

3. Periodic Table of the Elements
Metals
Non-Metals

4. Naming Ionic Compounds
Two word name
First word- name of first element in formula
Second word- name of second element with ending changed to “ide”
Ex: NaCl KF
Li2O
sodium
chloride
chlorine
potassium
fluoride
fluorine
lithium
oxide
oxygen

5. Practice: Write the name of the following ionic compounds
MgS
CaF2
AlBr3
ZnI2
Mg3N2
magnesium sulfide
calcium fluoride
aluminum bromide
zinc iodide
magnesium nitride

6. How do we know if a compound is ionic?
Recap
How do we know if a compound is ionic?
Metal & Non-metal

7. Writing Formulas for ionic compounds
Write formula for sodium chloride.
Start with a picture of the ions:
Na+ Cl-
Note: Amount of charge tells how many hooks
Formula:
NaCl
Cl-
Na+
Another example: sodium oxide Na+ and O2-
O-2
Na+
Formula:
Na2O
Na+

8. Writing Formulas for ionic compounds, cont’d
A third example: aluminum sulfide Al3+ and S2-
S-2
Al3+
Formula:
Al2S3
S-2
Al3+
S-2

9. Writing Formulas for ionic compounds
We can also use a shortcut method for finding the formulas for ionic compounds:
Identify the ions and their charges.
Rewrite elements. Cross over the charges and rewrite them as subscripts.
Put both parts together and write the subscripts in the simplest form.
Example: calcium chloride
Ca2+
Cl- Ca Cl 2
CaCl2
ANSWER

10. Practice Problems
Determine the formulas of the following ionic compounds:
Lithium fluoride
Magnesium bromide
Calcium selenide
Beryllium iodide
Scandium sulphide
Strontium oxide
Potassium phosphide
Aluminum oxide
LiF
MgBr2
CaSe
BeI2
Sc2S3
SrO
K3P
Al2O3

11. What’s the difference between a charge
Question
What’s the difference between a charge
and a subscript?
A charge tells us how many electrons an element has gained or lost to become an ion.
A subscript is used in the written formula of a compound to tell us how many molecules of a certain element are used in that compound.

12. Ionic Compounds with polyatomic ions
Ion composed of more than one element
Examples:
OH- hydroxide
ClO3- chlorate
SO42- sulfate/sulphate
*More polyatomic ions are listed on the ion side of
your periodic table.
Note:
The charge on a polyatomic ion is on all the listed elements together as a whole. When O and H are together they have a charge of -1.

13. Naming Ionic Compounds with polyatomic ions
Two word name
First word- name of first element in formula
Second word- name of polyatomic ion
Ex: NaOH
Mg(CN)2
Li2CO3
Another one:
NH4Cl
sodium
hydroxide
magnesium
cyanide
lithium
carbonate
ammonium
chloride

14. Practice: Write the name of the following ionic compounds.
Mg(OH)2
CaC2O4 = CaOOCCOO
NH4Br
Zn(BrO3)2
Mg3(BO3)2
Magnesium hydroxide
Calcium oxalate
Ammonium bromide
Zinc bromate
Magnesium borate

15. Writing Formulas for ionic compounds (with polyatomic ions)
An example: sodium hydroxide Na+ and OH-
Formula:
NaOH
OH-
Na+

16. Writing Formulas for ionic compounds (with polyatomic ions), cont’d
Another example: barium sulfite Ba2+ and SO32-
Formula:
BaSO3
SO3 -2
Ba2+

17. Writing Formulas for ionic compounds (with polyatomic ions), cont’d
Another example: aluminum sulfate Al3+ and SO42-
SO4 -2
Al3+
Formula:
Al2(SO4)3
SO4 -2
Al3+
SO4 -2

18. Writing Formulas for ionic compounds (with polyatomic ions), cont’d
Another example: calcium nitrate Ca+2 and NO3-
NO3-
Ca+2
Formula:
Ca(NO3)2
NO3-

19. Writing Formulas for ionic compounds (with polyatomic ions): criss-cross
An example: sodium hydroxide Na+ and OH- Na OH
Formula:
NaOH

20. Writing Formulas for ionic compounds (with polyatomic ions), cont’d
Another example: barium sulfite Ba2+ and SO32- Ba SO3 BaSO3 2 2
Formula:
BaSO3

21. Writing Formulas for ionic compounds (with polyatomic ions), cont’d
Another example: aluminum sulfate Al3+ and SO42- Al SO4 3 2
Formula:
Al2(SO4)3

22. Practice Problems Ca(CN)2 Calcium cyanide Be(OH)2 Beryllium hydroxide
Li2CO3
(NH4)2CrO4
Calcium cyanide
Beryllium hydroxide
Lithium carbonate
Ammonium chromate

23. Polyatomic Ions Worksheet

24. Multivalent Ionic Compounds
Some ions can have more than one possible charge.
This is indicated on the periodic table of the ions by dividing the box in half.
Ex:
Note:
Roman numerals are used to indicate the charge of the ion.
Titanium (IV)
Titanium (III)
Roman numerals (1-5): I, II, III, IV, V

25. Naming Multivalent Ionic Compounds
Example: Ti2O3
titanium
(III)
oxide
Two word name
First word- name of first element in formula with charge indicated by roman numeral
Second word- name of second element with “ide” ending

26. Naming Multivalent Ionic Compounds
Example: CoF2
cobalt
(II)
fluoride
Two word name
First word- name of first element in formula with charge indicated by roman numeral
Second word- name of second element with “ide” ending

27. Naming Multivalent Ionic Compounds
Example: Mn(OH)4
manganese
(IV)
hydroxide
Two word name
First word- name of first element in formula with charge indicated by roman numeral
Second word- name of second element/polyatomic compound with “ide” ending

28. Naming Multivalent Ionic Compounds
Example: CrS
chromium
(II)
sulfide
Two word name
First word- name of first element in formula with charge indicated by roman numeral
Second word- name of second element/polyatomic compound with “ide” ending

29. Practice Name the following multivalent ionic compounds: NiCl3 CuBr
Fe(CN)3
CoP
VF5
VS2
nickel (III) chloride
copper (I) bromide
iron (III) cyanide
cobalt (III) phosphide
vanadium (V) fluoride
Vanadium (IV) sulfide

30. Writing Formulas for multivalent ionic compounds
Example: copper (II) nitride Cu2+ and N3- Cu N Cu3N2 3 2
Formula:
Cu3N2

31. Writing Formulas for multivalent ionic compounds
Example #2: iron (III) hydroxide Fe3+ and OH- Fe OH Fe(OH)3 1 3
Formula:
Fe(OH)3

32. Practice Problems Name the following multivalent ionic compounds: CuF
Mn3P2
Cr3N2
PdO
Ti2O3
Cr2S3
Ru2S
TiHS4
NiCl3
FePO4
V3N5
Cu(NO2)2
CuBr2
Pd(OH)3

33. Practice Problems iron (III) sulfide Chromium (II) oxide
Write the formula for each multivalent ionic compounds:
iron (III) sulfide
Chromium (II) oxide
Copper (II) phosphide
Nickel (III) bromide
Lead (IV) sulfate
Vanadium (V) cyanide