Physical Properties
Oxtoby, pp. 314-317

Ligand Binding
Oxtoby, pp. 324-327

Coordination Complexes
Oxtoby, pp. 328-329

Introduction
Most of the familiar metallic elements are transition metals, a large block of elements which occupies the central region of the periodic table. Iron, cobalt, nickel, copper, silver, tungsten, gold, and platinum are familiar examples of transition metals.

A characteristic property of these elements is the relatively low reactivity of the parent metals and their alloys. For this reason, in combination with their attractive physical properties, they are useful as structural materials. Despite their considerable chemical inertness the transition metals can be oxidized, and only the more unreactive of them--copper, silver, gold, and platinum--occur appreciably in nature as the native metals. The rest are found exclusively in minerals containing the oxidized element, often as an oxide, sulfide, or carbonate (e.g. Fe₂O₃, NiS, FeCO₃). Since most of these minerals are insoluble in water, transition metal cations are present in natural water systems only at very low concentrations. For instance, the abundance of iron in the earth's crust is 4.7% by weight compared to 2.6% for sodium. In sea water, however, sodium is more abundant than iron by a factor of 2 × 10⁶.