ABSTRACT
According to the previous nomenclature system of the Periodic Table, the elements of the three groups 8, 9, and 10, were included in one Group VIII. The old system referred to chemical and geochemical properties of the elements and therefore it was easier to compare and describe these elements. However, the new nomenclature system is now obligatory. The Group 8 of the New Periodic Table of Elements (after the latest IUPAC recommendation) is composed of three elements: iron (Fe), ruthenium (Ru), and osmium (Os). These elements exhibit highly variable states of oxidation, as well as various properties (Table 13.1).
