You will be given a definition of a task first, then some input of the task.
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.

One coupling reaction links an aryl halide with an acetylide of this metal, while in another reaction it is used as a catalyst to link an alkyne and a bromoalkyne. In addition to the Castro-Stephens and the Cadiot-Chodkiewicz coupling, alkenyl compounds of this element can be created via the Normant reaction. The iodide of this element is a catalyst in the (*) Gatterman-Koch reaction, and this element is present in the A solution of the Fehling test. Gilman reagents contain lithium and this other metal, while the 2+ ion of this element forms a bright blue solution. For 10 points, name this element, a metal used in electroplating and plumbing, with atomic number 29 and symbol Cu.
Output:
Science