1. Chemical Names and Formulas
Nomenclature

2. Naming Monatomic Ions
Monatomic ions – single atom with a (+) or (-) charge
Cations
Group 1A, 2A, and 3A elements
Name is the same as the metal followed by the word ion or cation
examples
Na+ - sodium ion or sodium cation
Ca2+ - calcium ion or calcium cation

3. Naming Monatomic Ions Anions Groups 5A, 6A, & 7A
The name is not the same as the element’s name
< different from the rules for naming cations>
Start with the stem of the element name and end in –ide.
Examples
fluorine (F-)  fluoride ion
oxygen (O-2)  oxide ion
Nitrogen (N-3)  nitride ion
Group 4A and 8A elements do not usually form ions
Now it’s your turn! Do the problems corresponding to the naming monatomic ions heading.

4. Ions of Transition Metals
The charges of the cations of many transition metals must be determined by the number of electrons lost
Some transition metals can more than one ion with different charges.

5. Table 9.2 Symbols Common Metal Ions with More than One Ionic Charge
Cu+
Cu2+
Fe2+
Fe3+
Hg22+
Hg2+
Pb2+
Pb4+
Sn2+
Sn4+
Cr2+
Cr3+
Mn2+
Mn3+
Co2+
Co3+

6. Ions of Transition Metals
There are 2 methods for naming the ions of transition metals
The Stock System and the classical names
The Stock System is the preferred
Stock System
A roman numeral in parentheses is placed after the name of the element(metal) to indicate the numerical value of the charge.
Do not leave a space between the element name and the roman numeral in parentheses
Example
Fe2+ iron(II) ion  should be read as “iron two ion”
Cu2+ copper(II) ion  “copper two ion”

7. Ions of Transition Metals
Classical Names  not the preferred method, however you must know it.
Uses a root word with different suffixes at the end of the word
The suffix –ous is used to name the cation with the lower of the two ionic charges
The suffix –ic is used to name the cation with the higher of the two ionic charges.
Examples
ferrum is latin for iron therefore ferr- is the root of the word
Fe2+ - ferrous ion
Fe3+ - ferric ion
stannous is latin for tin therefore stann- is the root of the word
Sn2+ - stannous ion
Sn4+ - stannic ion

8. Ions of Transition Metals
Classical Names
Disadvantages
Does not tell you the actual charge
Only tells you whether the cation has the smaller or larger of the charges
A few transition metals have only one charge
Do not use roman numerals when using the stock system
Some of these exceptions are
silver - Ag+, cadmium – Cd2+, & zinc2+
Now it’s your turn! Complete the section also labeled Ions of Transition Metals

9. Polyatomic Ions Composed of more than one atom
The names of polyatomic anions end in –ite or –ate
Examples
Hypochlorite – ClO-
Hydrogen carbonate (HCO3-)
Three common polyatomic ions have different endings
Ammonium ion (NH4+)
Cyanide ion (CN-)
Hydroxide (OH-)

10. Polyatomic Ions
Sometimes the same elements combine in different ratios to form different polyatomic ions
Examine the following chart, what do you notice?
-ite
-ate
SO32-, sulfite
SO42-, sulfate
NO2-, nitrite
NO3-, nitrate
ClO2-, chlorite
ClO3-, clorate

11. Polyatomic Ions
If the formula begins with H (hydrogen) think of it as representing the hydrogen ion H+ combined with another polyatomic ion.
The charges of the new ion is the sum of the 2 original ion charges

12. Common Polyatomic Ions

13. Naming and Writing Formulas for Ionic Compounds

14. Binary Ionic Compounds
Antoine-Laurent Lavoisier worked to identify the composition of many compounds
Worked with other chemists to develop a system for naming compounds – the chemical names today are based on their work
Binary compound – composed of two elements and can be ionic or molecular
If you know the formula of an ionic compound, it is easy to write the name
Place the cation name first, followed by the anion name

15. Binary Ionic Compounds
For ionic compounds that contain metals with only one possible charge it is simple
Cs2O  Cs- cesium(the cation), O – oxygen (the anion)  cesium oxide
NaBr  Na – sodium (cation) , Br – bromine (anion)  sodium bromide
SrF2  Sr – strontium (cation), F – fluorine (anion)  strontium fluoride
What about elements with transition metals that can have different ionic charges?
You must use the stock system or the classical name for the cation
Stock System
CuO – copper(II) oxide
Cu2O – copper(I) oxide
How do you know which cation formed each compound?
Work backwards

16. Binary Ionic Compounds
CuO – copper(II) oxide
Cu2O – copper(I) oxide
The formulas indicate the ratios
CuO - the copper cation and the oxide anion combine in a 1:1 ratio
The oxide ion always has a charge of 2-
The charge of the copper cation must be 2- to balance the charge
Cu2O – the copper cation and the oxide anion combine in 2:1 ratio
You need to +1 cations to balance the charge

17. Binary Ionic Compounds
Using the classical names for the ions
SnF2 and SnS2
The fluoride anion has a charge of -1 and the sulfur anion has a charge of -2
SnF2
The ratio of Sn to F is 1:2 therefore the charge of Sn must be +2 to balance the -2 charge of the two fluoride anions
stannous fluoride  because +2 is the lower of the ionic charges for tin
SnS2
The ratio of Sn to S is 1:2, S is a -2 so to balance the -4 charge of S anions the charge of tin must be +4
Stannic sulfide  because +4 is the higher of the ionic charges for tin

18. Writing formulas for Binary Ionic Compounds
If you know the name of the binary ionic compound, it is simple to write the formula
Write the symbol of the cation and then the anion. Add the subscripts necessary to balance the charges.
Remember the net ionic charge must = 0.
Potassium chloride
K+ Cl-
The charge of each K+ is balanced by the charge of each Cl- therefore the ratio is 1:1  KCl
Calcium bromide
Ca+2 Br-
The charge of each Ca+2 ion must combine with 2 Br- anions to balance the charges  CaBr2

19. Writing Formulas for Binary Ionic Compounds
You can also use the crisscross method.
The numerical value of the charge of each ion becomes the subscript for the other ion.

20. Writing Formulas for Binary Ionic Compounds

21. Compounds with Polyatomic Ions
-ate or –ite ending indicates a compound with a polyatomic ion that includes oxygen
Writing the chemical formula requires the same process.
Write the symbols and then add the subscripts necessary to balance the charge
Examples
Calcium carbonate
Ca+2 CO32-  1:1 ratio  CaCO3
Calcium nitrate
Ca NO3-  1:2 ratio  Ca(NO3)2  Use parentheses around the polyatomic ion when more than one is required to balance the charges and place the subscript after the parentheses.
The criss-cross method can also be used

22. Naming Compounds with Polyatomic Ions
When given the formula
1st – recognize that the compound contains a polyatomic ion
Yes it will be necessary for you to memorize the common polyatomic ions!!
2nd – state the cation first and then the anion
Examples
LiCN – lithium cyanide
NaClO – sodium hypochlorite (ClO-)  this is a polyatomic ion with the name hypochlorite because it has one less oxygen than ClO2- which is has the name chlorite.