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]: An approximation of it named for Russell uses the TDS value to determine one of its parameters via the Langelier approximation, while one constant that appears in it has units of moles per kilogram to the one half power, according the Bates-Guggenheim convention. Along with Guggenheim, Scatchard and Bronsted improved upon this model by developing the SIT theory, and that model has a better fit than a modification of it named for Davies. This relationship assumes the existence of only long-range interactions, and it was extended to account for Brownian motion by Lars Onsager. It assumes that the solvent is structure-less and that the solution is dilute, and the theory behind it implies that the electrostatic potential falls off exponentially when r is greater than the atomic radius due to screening by counter ions. For 10 points, identify this equation which is used to calculate the activity coefficients, and is named for a German and a Dutch scientist. 
[A]: Science


[Q]: LDA is used to transform propargyl diol into one of these compounds in the Whiting reaction. A  useful one of these compounds is synthesized using zinc chloride to combine trimethylsilyl chloride  with methoxybutenone. The namesake value of these compounds is expressed as the mass of iodine  equivalent to the amount of (*) maleic anhydride reacting with a unit mass of one of these. The  cumulated type of these compounds are less stable than other types. Electrophilic addition can result in  both 1,2 and 1,4 additions in the conjugated type of these molecules. That type also undergoes a type of  reaction that follows the endo addition rule and forms cyclohexenes, the Diels-Alder reaction. For 10  points, name these hydrocarbons that contain two carbon-carbon double bonds.
[A]: Science


[Q]: This molecule is released by climbing fiber activation of Purkinje cells, and Huntington's disease is\n partially caused by the loss of cells that secrete this substance in the striatum. It is produced in a reaction\n that uses the enzymes GAD and pyridoxal phosphate, or vitamin B6 and its receptor works by widening a\n chloride channel, which in turn neutralizes norepinephrine. Benzodiazepenes and barbituates work by\n binding to receptors for this molecule, which is synthesized by decarboxylating glutamate. For 10 points,\n name this inhibitory mammalian neurotransmitter with a four letter abbreviation.
[A]:
Science