Group 8 is a
group (column) of
chemical elements in the
periodic table
The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of ch ...
. It consists of
iron (Fe),
ruthenium (Ru),
osmium
Osmium (from Greek grc, ὀσμή, osme, smell, label=none) is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mos ...
(Os) and
hassium (Hs).
[Leigh, G. J. ''Nomenclature of Inorganic Chemistry: Recommendations 1990''. Blackwell Science, 1990. .] They are all
transition metals.
Like other groups, the members of this family show patterns in
electron configuration
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. For example, the electron configuration of the neon atom ...
, especially in the outermost shells, resulting in trends in chemical behavior.
"Group 8" is the modern standard designation for this group, adopted by the
IUPAC in 1990.
[
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).
Group 8 (current IUPAC) should not be confused with "group VIIIA" in the CAS system, which is group 18 (current IUPAC), the noble gases.
While groups (columns) of the periodic table are sometimes named after their lighter member (as in "the oxygen group" for group 16), the term iron group does ''not'' mean "group 8". Most often, it means a set of adjacent elements on period (row) 4 of the table that includes iron, such as ]chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
, manganese, iron, cobalt, and nickel, or only the last three, or some other set, depending on the context.
Basic properties
The first three elements are hard silvery-white metals. Hassium has not been isolated in macroscopic pure form, and its properties have not been conclusively observed.
References
{{DEFAULTSORT:Group 08
Groups (periodic table)