Group 9 element Group 9 element Group 9, numbered by IUPAC nomenclature, is a group of chemical element in the periodic table. Members are cobalt (Co), rhodium (Rh), iridium (Ir) and perhaps also the chemically uncharacterized meitnerium (Mt). These are all transition metals in the d-block. All known isotopes of meitnerium are radioactive with short half-lives, and it is not known to occur in nature; only minute quantities have been synthesized in laboratories. 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.
Cobalt(II) oxide Cobalt(II) oxide Cobalt(II) oxide or cobalt monoxide is an inorganic compound that appears as olive-green to red crystals, or as a greyish or black powder. It is used extensively in the ceramics industry as an additive to create blue colored glazes and enamels as well as in the chemical industry for producing cobalt(II) salts. CoO crystals adopt the periclase (rock salt) structure with a lattice constant of 4.2615 Å. It is antiferromagnetic below 16 °C. Cobalt(II,III) oxide decomposes to cobalt(II) oxide at 950 °C: Though commercially available, cobalt(II) oxide may be prepared in the laboratory by electrolyzing a solution of