1. Ions Monatomic Ions Ion Formulas and Names
Chapter 10 & 7A
Ions
Monatomic Ions
Ion Formulas and Names

2. Ion Vocabulary An ion is an atom or group of atoms that have a charge.
A cation is a positive ion.
An anion is a negative ion.

3. If a neutral atom loses one or more electrons it becomes a cation.Na
11 protons
11 electrons
Na+
11 protons
10 electrons
If a neutral atom gains one or more electrons it becomes an anion. Cl
17 protons
17 electrons
Cl-
17 protons
18 electrons

4. Atoms tend to lose and gain electrons when they bond with other atoms in an attempt to become more stable.

5. Why is Na+ more stable than Na
Na = 1s22s22p63s1

6. Why is Na+ more stable than Na
Na = 1s22s22p63s1
Lose 1 e-
Na+ = 1s22s22p6

7. Why is Na+ more stable than Na
Na = 1s22s22p63s1
Lose 1 e-
Na+ = 1s22s22p6
This is isoelectronic (has similar properties..) with Ne

8. Why is Clˉ more stable than Cl
Cl = 1s22s22p63s23p5

9. Why is Clˉ more stable than Cl
Cl = 1s22s22p63s23p5
Gain 1 e-
Clˉ = 1s22s22p63s23p6

10. Why is Clˉ more stable than Cl
Cl = 1s22s22p63s23p5
Gain 1 e-
Clˉ = 1s22s22p63s23p6
This is isoelectronic with Ar

11. Determine the number of protons and electrons for each ion and state what noble gas each is isoelectronic with. Mg
12 protons
12 electrons
Mg2+
___ protons
___ electrons
___ isoelectronic
O2-
___ protons
___ electrons
___ isoelectronic O
8 protons
8 electrons

12. Why is lithium oxide Li2O
Ionic bonding: Li + O
Why is lithium oxide Li2O
3p+
4n0
2e-1e-
8e- 2e-
8n0
8p+
3p+
4n0
2e-
1e-
6e- 2e-
8n0
8p+
3p+
4n0
2e-1e-
1e- O Li
[ O ]2–
[Li]2+

13. Ion Vocabulary A monatomic ion is an atom with a charge.
The charge on a monatomic ion is called an oxidation number.
A polyatomic ion is a group of atoms with a charge.

14. Types of monatomic ions and the rules for naming them
The periodic table is useful in naming the monatomic ions.

15. Monatomic cations with one oxidation number
The cations from the periodic table which have a single oxidation number are as follows: Group 1 (+1), Group 2 (+2), Ag+, Cd2+, Zn2+, and Al3+.
These types of ions are named by using the name of the element followed by the word ion.
Na+ sodium ion
Ba2+ barium ion
Zn2+ zinc ion
We can use the roman numeral from the periodic table to identify the oxidation number for these ions.

16. Monatomic cations with multiple oxidation numbers
All other cations that are not listed in the previous category (“cations with one oxidation number”) are considered to have the possibility of multiple oxidation numbers.
These type of ions are named by using the name of the element followed by a Roman numeral to indicate the oxidation number.
Cu2+ copper (II)
Pb4+ lead (IV)
Mn7+ manganese (VII)
It is important to note that the roman numerals in these names may or may not be the roman numeral from the periodic table.
All atoms other than F or the noble gases can form positive ions.

17. Negative Monatomic anions
All anions from the periodic table are named by changing the ending of the element’s name to –ide.
F- fluoride ion
O2- oxide ion
N3- nitride ion
Count back from the noble gases starting at zero to determine the oxidation number.

18. Ask Yourself 3 Questions.
Does the name end with: Ion? Roman numeral? -ide?

19. Name these monatomic ions
Rb+
P3-
Fe3+
Br‾
Mn4+
Cd2+
Rubidium ion
Phosphide
Iron III
Bromide
Manganese IV
Cadmium ion

20. Write the formula for these monatomic ions.
Sulfide
Lead (II)
Barium ion
Chromium (IV)
Aluminum ion
Carbide
S2-
Pb2+
Ba2+
Cr4+
Al3+
C4-

21. Atoms of elements and Ions of elements are different

22. Atoms of elements
Sodium is a soft, silvery highly reactive metal. It is used in making light bulbs and for heat exchange in nuclear reactors.
A pale yellow-green gas, chlorine killed soldiers in WWI. Today it primarily used to kill bacteria in water.

23. Ions of elements
Combined together sodium and chlorine make common table salt and are thus essential to life. Table salt consists of sodium ions (Na+) and chloride ions (Cl-)

24. Steps for Naming Ions Name polyatomic ions. -ide, ion, Roman numeral?
Name remaining anions (change ending to –ide)
Name remaining cations from groups 1, 2, Ag+, Cd2+, Zn2+, Al3+. (use the name of the element and add “ion”)
Name all remaining cations using the name of the element followed by a roman numeral equal to the positive charge of the cation.

25. Ag+
7. Cu+
8. NH4+
9. P3-
10. Cl3+

26. Steps for Writing Formulas of Ions
Many people find that they wish to do these in the order that they are presented. You can however do them in 4 sets.
Polyatomic ions.
Remaining anions. (These will be anything left that ends in –ide).
Remaining ions containing a Roman Numeral.
Remaining ions without a Roman Numeral. (Groups 1 & 2, silver, cadmium, zinc, aluminum).

27. 6. Hydroxide ion
7. Cadmium ion
8. Lithium ion
9. Calcium ion
10. Mercury (I) ion