Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

A substitution creating a bond between this element and a ligand is used to determine the Tolman electronic parameter. This element's acetylacetonate is used to prepare a complex in which it is bound to two cyclo-octa-diene molecules, which serve as donors of its "zero" form. Using this metal as a catalyst in the Fischer-Tropsch process tends to favor the formation of methane. It's not titanium or aluminum, but during the development of Ziegler- Natta catalysts it was discovered that impurities of this element stopped the reaction at 1-butene. The process used to purify this element creates its tetracarbonyl by adding a bunch of (*) carbon monoxide in one step. It's not palladium, but several catalysts for the Negishi and Kumada couplings use this element. The Mozingo process is catalyzed by this element, and that process involves the removal of a thioketal group after protecting a carbonyl. A catalyst containing an alloy of it and aluminum is activated by sodium hydroxide; that catalyst is used for hydrogenation and named for Raney. For 10 points, name this transition metal.
Science