Monatomic Ions

1
Monatomic Ions
2
Ion Vocabulary

• An ion is an atom or group of atoms that have a
  charge.
• A monatomic ion is an atom with a charge.
• The charge on the atom is called an oxidation
  number.
• A polyatomic ion is a group of atoms with a
  charge.
• A cation is a positive ion.
• An anion is a negative ion.

3
Types of monatomic ions and the rules for naming
them

• The periodic table is useful in naming the
  monatomic ions.

4
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.

5
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. In other words
  the periodic table is of little or no help in
  determining their oxidation numbers.

6
Monatomic anions

• All anions from the periodic table are named by
  changing the ending of the elements 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.

7
Name these monatomic ions

• Rb
• P3-
• Fe3
• Br?
• Mn4
• Cd2

Rubidium ion Phosphide Iron III Bromide Manganese
IV Cadmium ion
8
Write the formula for these monatomic ions.

• Sulfide
• Lead (II)
• Barium ion
• Chromium (IV)
• Aluminum ion
• Carbide

S2- Pb2 Ba2 Cr4 Al3 C4-
9
Atoms of elements and Ions of elements are
different
10
Atoms of elements
A pale yellow-green gas, chlorine killed soldiers
in WWI. Today it mainly purifies drinking water
and swimming pools.
Sodium is a soft, silvery highly reactive metal.
It is used in making light bulbs and for heat
exchange in nuclear reactors.
11
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-)