Group 12 element precludes there being much common chemistry between mercury and gold, though there are similarities between mercury(I) and gold(I) such as the formation of linear dicyano complexes, [M(CN)]. According to IUPAC's definition of transition metal as "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell", zinc and cadmium are not transition metals, while mercury is. This is because only mercury is known to have a compound where its oxidation state is higher than +2, in mercury(IV) fluoride (though its existence is disputed, as later experiments trying to confirm its
Group 6 element The metals form compounds in different oxidation states: chromium forms compounds in all states from −2 to +6: disodium pentacarbonylchromate, disodium decacarbonyldichromate, bis(benzene)chromium, tripotassium pentanitrocyanochromate, chromium(II) chloride, chromium(III) oxide, chromium(IV) chloride, potassium tetraperoxochromate(V), and chromium(VI) dichloride dioxide; the same is also true for molybdenum and tungsten, but the stability of the +6 state grows down the group. Depending on oxidation states, the compounds are basic, amphoteric, or acidic; the acidity grows with the oxidation state of the metal. Tungsten has no known biological role in the human body. Seaborgium's high radioactivity would make it a toxic element, due to radiation