1. Naming Ions

2. What is a Monatomic Ion?
A monotomic ion consists of a single atom with a positive or negative charge resulting from the loss or gain of valence electrons
A cation is an ion with a positive charge. Metals in groups 1A, 2A, and 3A form a cation with the same charge as their group number
The names of cations in these groups is the name of the element followed by ion or cation.
Example: Na+ is sodium ion or sodium cation
Ca2+ is calcium ion or calcium cation

3. Naming Anions
An anion is an atom that has gained electrons and thus has a negative charge
The charge of a nonmetal anion in group A is determined by subtracting 8 from the group number.
Elements in group 7A have a charge of -1 (7-8=-1)
The name of an anion is not the same as the element’s name
Anion names have the root of the element name with – ide added to it.
Example: A chlorine ion is called chloride, and oxygen ion in called oxide

4. Fluorine Ion Bromine Ion Selenium Ion Nitrogen Ion Fluoride Bromide
Practice
Fluorine Ion
Bromine Ion
Selenium Ion
Nitrogen Ion
Fluoride
Bromide
Selenide
Nitride

5. Ions of Transition Metals
Transition metals do not form consitant charges when ioninzing like elements in the A group
They can form multiple ions
Iron can form Fe2+ and Fe3+
These cations are named differently than others.
When naming an ion of a transition metal, write the name of the element folowed by it’s charge written in roman numerals following it.
Example: Fe2+ is written as iron (II) and Fe3+ is written as iron (III)

6. Exceptions Some transition metals have only one ionic charge.
The names of these elements do not have a roman numeral
These excepetions include silver (Ag+), cadmium (Cd2+), and zinc (Zn2+)

7. Pb2+ Pb4+ Cr2+ Cr3+ lead (II) lead (IV) chromium (II) chromium (III)
Practice
Pb2+
Pb4+
Cr2+
Cr3+
lead (II)
lead (IV)
chromium (II)
chromium (III)

8. Polyatomic Ions
A polyatomic ion is an ion composed of more than one atom.
The names of most polyatomic ions in in –ite or –ate.
All polyatomics ending in –ite or –ate contain oxygen

9. 1+ ammonium NH4+ 1- acetate C2H3O2- chlorate ClO3- hydroxide OH-
Charge
Name
Formula 1+
ammonium
NH4+ 1-
acetate
C2H3O2-
chlorate
ClO3-
hydroxide
OH-
cyanide
CN-
nitrate
NO3-
nitrite
NO2-
perchlorate
ClO4-
permanganate
MnO4- 2-
carbonate
CO32-
sulfate
SO42-
sulfite
SO32- 3-
phosphite
PO33-
phosphate
PO43-

10. Adding Hydrogen
When the formula for a polyatomic ion contains hydrogen, it is a combination of an H+ ion and another polyatomic ion
H+ + CO32- (carbonate) -> HCO3- hydrogen carbonate
H+ + PO43- (phosphate) -> HPO42- hydrogen phosphate

11. Naming Compounds with Polyatomic Ions
Naming a compound with a polyatomic ion works the same as with other ionic compounds
Name the cation first then the anion
Use the name of the polyatomic ion when naming.

12. Example

13. Naming and Writing Ionic Compounds

14. What is a Binary Ionic Compound
A binary ionic compound is composed of two elements joined by an ionic bond.
To name a binary ionic compound place the name of the cation first, followed by the name of the anion.
The compound must remain neutral
Example: NaBr would be sodium bromide
Example: CuO would be copper (II) oxide
This is known because the charge of oxygen is a 2-, so copper must have a charge of 2+ for the compound to be neutral

15. Cu2O
SnF2
SnS2
copper (I) oxide
tin (II) fluoride
tin (IV) fluoride

16. Writing formulas for binary ionic compounds
If you know the name of a binary ionic compound, you can write it’s formula
The net charge of the compound must be zero
First figure out the charge of the atoms in the name of the compound
Then use the charge of one compound as the subscript for the other compound
Then reduce to the lowest whole number ratio

17. Example Write the formula for calcium sulfide
From the periodic table, the charge of calcium is 2+
From the periodic table, the charge of sulfur is
6 -8 = -2 or S2-
Ca2+ and S2- crossing the charges gives Ca2S2
Reducing to the lowest whole number ratio gives CaS

18. Example Write the formula for iron (III) oxide
From the name of the ionic compound, the charge of iron is Fe3+
From the periodic table, the charge of oxygen is
6 -8 = -2 or O2-
Fe3+ and O2- crossing the charges gives Fe2O3

19. Practice
copper (II) sulfide
potassium nitride
CuS
K3N

20. Compounds with Polyatomic Ions
Compounds with polyatomic ions behave the same as those without
The method for writing their formula is the same as ordinary ionic compounds, except you look up the charge from a table of polyatomic ions instead of the periodic table

21. Example Write the formula for calcium nitrate
From the periodic table, the charge of calcium is 2+
From the polyatomic table, the charge of nitrate is 1-
Ca2+ and NO3- crossing the charges gives Ca(NO3)2
For a polyatomic ion, the subscript is written on the outside of the parenthesis