| Group 8 in the periodic table | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| |||||||||
| ↓ Period | |||||||||
| 4 |  26 Transition metal | ||||||||
| 5 |  44 Transition metal | ||||||||
| 6 |  76 Transition metal | ||||||||
| 7 | Hassium (Hs) 108 Transition metal | ||||||||
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Legend
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Group 8 is a group (column) of chemical elements in the periodic table. It consists of iron (Fe), ruthenium (Ru), osmium (Os) and hassium (Hs).[1] "Group 8" is the modern standard designation for this group, adopted by the IUPAC in 1990.[1] It should not be confused with "group VIIIA" in the CAS system, which is group 18 (current IUPAC), the noble gases. In the older group naming systems, this group was combined with groups 9 and 10 and called group "VIIIB" in the Chemical Abstracts Service (CAS) "U.S. system", or "VIII" in the old IUPAC (pre-1990) "European system" (and in Mendeleev's original table). The elements in this group are all transition metals that lie in the d-block of the periodic table.
While groups (columns) of the periodic table are usually named after their lightest member (as in "the oxygen group" for group 16), iron group has historically been used differently; most often, it means a set of adjacent elements on period (row) 4 of the table that includes iron, such as chromium, manganese, iron, cobalt, and nickel, or only the last three, or some other set, depending on the context.
Like other groups, the members of this family show patterns in electron configuration, especially in the outermost shells, resulting in trends in chemical behavior.
- ^ a b Leigh, Geoffrey J. (1990). Nomenclature of inorganic chemistry: recommendations 1990. Union internationale de chimie pure et appliquée. Oxford London Edinburgh: Blackwell scientific publ. ISBN 978-0-632-02494-0.