Zirconium and Hafnium

Abstract Zirconium and hafnium belong to the group IVB of the periodic table. A characteristic feature of these transition elements is the ease with which they form stable complex ions. Features that contribute to this ability are favorably high charge‐to‐radius ratios and the availability of unfilled d orbitals. The ability of forming metallic bonds is demonstrated by the existence of a wide variety of alloys among different transition metals. Other features of these metals are high densities, high melting points, and low vapor pressures. Within this group, these properties tend to increase with increasing atomic weight. This chapter discusses the chemical and physical properties followed by the toxicity of each chemical and compound in two sections: the first section provides details on zirconium, and the second section on hafnium.