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.

[EX Q]: One reactant for this reaction is best prepared by an S N 2 nucleophilic addition of a triphenyl compound, followed by elimination of the hydrogen halide by an organolithium reagent. This reaction itself proceeds through a rather unique intermediate formed when the pi electron from the reagents carbon-oxygen double bond migrates to the positively charged pole of one reactant; this intermediate is called a an oxaphosphetane, from which a triphenyl oxide is eliminated to complete the reaction. The aforementioned positively charged pole is on phosphorous because the aforementioned prepared reactant is a phosphorous ylide. For ten points, name this reaction that produces selectively double-bonded alkenes from aldehydes and phosphorous ylides and that is named for the German 1979 Chemistry Nobel winner.
[EX A]: Science

[EX Q]: The yield of these compounds can be increased through ball milling of some of their components, and one mode of operation of these compounds proceeds through a mechanism called enantiomorphic site control. A process for the operation of these compounds that proceeds through migratory insertions and obeys the "principle of least nuclear motions" was developed by Cossee and Arlman. Compounds such bis(cyclopentadienyl)titanium chloride and bis(indenyl)zirconium dichloride, known as metallocenes, have been developed as an alternative to the traditional compounds of this type. Those traditional initiators include vanadium trichloride and triethylaluminum, and the product of the application of these compounds to alkenes can result in syndiotactic, isotactic, or atactic products. For ten points, identify these stereoselective compounds used to initiate polymerization, named for a German and an Italian chemist.
[EX A]: Science

[EX Q]: In mass spectrometry, an aromatic cation with this many carbon atoms often appears at m over z equals 91. The signal for the central proton of an isopropyl group will have this many peaks in proton NMR. A violet-colored strong oxidizing agent has a metal in this oxidation state. That compound is potassium permanganate. This is the number of elemental gases that are diatomic at standard conditions. This integer is equal to the negative log of hydronium concentration of pure water at 25 degrees Celsius, and is also the number of valence electrons possessed by the most electronegative element, fluorine. For 10 points, give this number equal to the neutral pH value.
[EX A]:
Science