Group 9 element


Group 9 is a group of chemical elements in the periodic table. Members are cobalt, rhodium, iridium and meitnerium. These are all transition metals in the d-block.
Like other groups, the members of this family show patterns in electron configuration, especially in the outermost shells, resulting in trends in chemical behavior; however, rhodium deviates from the pattern.
"Group 9" 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 group 8 and group 10 and called group "VIIIB" in the Chemical Abstracts Service "U.S. system", or "VIII" in the old IUPAC "European system".

Chemistry

Predicted.
The first three elements are hard silvery-white metals. All known isotopes of meitnerium are radioactive with short half-lives. Only minute quantities have been synthesized in laboratories. It has not been isolated in pure form, and its physical and chemical properties have not been determined yet.