Categorize Ionic Compounds Depending on the Metal

• The first type (called Type I) contains a metal with an invariant charge—one that does not vary from one compound to another.
• The second type of ionic compound (called Type II) contains a metal with a charge that can differ in different compounds.
• Such metals are usually (but not always) found in the transition metals section of the periodic table.
• Some transition metals, such as Zn and Ag, form cations with the same charge in all of their compounds: Zn2+, Ag+.
• Some main group metals, such as Pb and Sn, form more than one type of cation.