Definition: 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.
Input: The allylation of nucleophiles with allylic halides is one example of the Tsuji-Trost reactions catalyzed by this element. Eaborn discovered that it can catalyze the reaction of aryl halides with hexa-n-butyldistannane, and more broadly it underlies the reaction of vinylic and aromatic systems with organostannanes in the Kosugi-Migita-Stille coupling. Also used for the coupling of alkenes and either halides or pseudohalides in the Mizoroki-Heck reactions, this element's chloride is reduced by calcium carbonate before lead acetate is added in the creation of a catalyst which is named for Lindlar. For 10 points, name this element, the least dense of the platinum group metals.
Output:
Science