| 1 | 2 | | | | | | | |
| Li+ | Be2+ | | | | | O2– | | |
| Na+ | Mg2+ | Al3+ | | | S2– | Cl– | |
| K+ | Ca2+ | | | | | Br– | |
| Rb+ | Sr2+ | | | | | I– | |
| Cs+ | Ba2+ | | Pb2+ | | | | |
The
cations in the table are the only monatomic ions formed by these elements. the ions are arranged in the order of the appearance of these elements in the groups in the periodic table.
The names of these have the element name followed by ion.Ca2+ is calcium ion and Na+ is sodium ion.
When writing the
formula from the name for Group 1, 2 and
metal ions recall that the magnitude of the positive charge is equal to the
last digit of the Group number.
Transition metals also form
monatomic cations as shown in the examples below.
Transition metals may form more than one ion, and, if so, these are given different names.
Iron forms Fe2+ and Fe3+. These are referred to as the iron(II) and iron(III) ions.
Copper forms Cu2+ (copper ion).
Zinc forms Zn2+ (zinc ion).
Silver forms Ag+ (silver ion).
The
anions in the table are the only monatomic ions formed by these elements.
Name these anions using the
first part of the element name plus
-ide.
Cl– chloride Br– bromide I– iodide
O2– oxide S2– sulfide
When writing the
formula of the ion from the name, note that the magnitude of the
negative charge is equal to the
Group number - .