Families of Element

At least two small family units can be identified within the larger transition-metal family. One of these small families, the coinage metals, consists of copper, silver and gold, the three elements in group 11. The other family, the platinum metals, includes elements from three groups: ruthenium and osmium from group 8; rhodium and iridium from group 9; and palladium and platinum from group 10.

The coinage metals are resistant to oxidation, hence their traditional use in making coins. Unlike the majority of the transition metals, the coinage metals each have a full d sublevel and one electron in an s sublevel, that is, an electron configuration that terminates in (n-1) d¹⁰ n s². One result of this electron configuration is that each of these metals will form an ion of the type M⁺, although it is only for silver that this ion is relatively stable.

The platinum metals occur together in the same ores, are difficult to separate from one another, and are relatively unreactive.