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.

[Q]: This element's only oxidation state is -1, and it is impossible to free from its compounds by chemical means. It is prepared commercially be the same method which Henri Moisson used to isolate it in 1886, and is also found in the mineral cryolite. Its only isotope is the stabe 19 version, and in its gaseous form takes on a pale yellow color. The most electronegative and reactive of the elements, FTP, what is this lightest of the halogens with atomic number 9 and symbol F
[A]: Science


[Q]: 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."
[A]: History


[Q]: There is still dispute over the discovery of a Baragwanathia fossil that allegedly lived during this period, as it would indicate the presence of lycophytes during it. Its latter portion saw a temporary reduction in conodonts as part of the Lau event, which occurred before its Pridoli epoch. Baltica's collision with Laurentia resulted in the beginning of the Iapetus Ocean's closure during its Ludlow Epoch, and this period saw the emergence of the first coral reefs. Other developments include the evolution of the first freshwater fish as well as the proliferation of bony and jawless fish coinciding with its significant glacial melt. Also seeing the development of Cooksonia, the first vascular land plants, for 10 points, name this period during the Paleozoic era, in between the Ordovician and Devonian periods.
[A]:
Science