instruction:
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.
question:
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.
answer:
Science

question:
One ruler of this name employed the general Aleksy Khvost in his war against Suzdal and Novgorod, and became known as ""the red. "" In addition to that father of (+) Dmitri Donskoy, this name was borne by the man who overthrew Alexander of Tver and became rich by collecting tribute on behalf of the Golden Horde, acquiring the nickname "moneybag." The (*) third ruler of this name stopped vassalage to the Horde and was known as "the great." For 10 points, give this name for several princes of Muscovy, including the first to take the title of Russian tsar, the fourth one known as "Grozny" or "the terrible."
answer:
History

question:
They are divided into two classes based on the ratio of the penetration depth to the coherence length, a quantity known as the Ginsburg-Landau parameter. Alexei Abrikosov discovered his namesake vortex lattice in one type, and the London equation describes a characteristic behavior of these materials similar to perfect diamagnetism. A complete theory of the type I variety of these substances, including the concept of the pairing of opposite-spin electrons over long distances, is known as the BCS theory. Discovered by Heike Kammerlingh-Onnes, FTP, identify these substances which exhibit zero electrical resistivity.
answer:
Science