An atom of this element sits at the center of the BCC unit cell of a Heusler (“HOYSE-ler”) alloy. This metal was doped into gallium nitride to form the first ferromagnetic semiconductor used in spintronics; similarly, a complex oxide containing twelve atoms of this spin-5/2 (“spin-five-halves”) metal was the first-known single-molecule magnet. (10[1])After reactions in acidic, neutral, and basic solutions, this element respectively speciates into +2 (“plus-2”), +4 (“plus-4”), and +6 (-5[1])(“plus-6”) oxidation states. Spinel oxide cathodes containing this metal, instead of cobalt, intercalate lithium in a commercial lithium battery and are reduced by zinc in a commercial alkaline battery. An oxide cluster containing this element and calcium (-5[1])splits water in the photosynthetic (10[2]-5[1])oxygen-evolving (10[2])complex. (10[2])This metal’s brown-colored (10[2])dioxide (10[3])precipitates when double (-5[1])bonds react with its +7 (“plus-7”) oxidation (10[1])state. (10[2]-5[1])For 10 points, name this transition metal found in a strong violet-colored (10[1])oxidizing agent. (10[1])■END■ (10[3]0[1])