TASK DEFINITION: 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.
PROBLEM: When these devices exploit their voltage-dependent variable capacitance they are known as varactors. Barring the creation of local hot spots, a non-destructive avalanche current is produced by electron-hole pair propagation when the electric field within the (*) depletion region of these devices reaches a critical value. Majority carriers exist in an energy state greater than the Fermi energy in the Schottky barrier variety and those that operate in reverse breakdown are named after Zener. For 10 pointsname these devices that allow current to pass in only one direction.

SOLUTION: Science

PROBLEM: Seas of calcite predominate during times of low concentration of this element. The NIMS probe discovered that Ganymede has a sulfate of this element, which is also used to treat eclampsia. Its molten form is used to make metallic titanium in the Kroll process. The active site of rubisco contains a carbamylated lysine attached to an ion of this element. Its cationic form is used to stabilize the product of PCR, and it is also prevalent in certain reagents in a Schlenck equilibrium. It is found in Grignard reagents as well as coordinated to the porphyrin ring of chlorophyll. For 10 points, name this element with atomic number 12 and symbol Mg.

SOLUTION: Science

PROBLEM: This non-Swiss artist's time in Munich produced an image of a red-hewed man facing away and blowing a conch horn next to a floating, topless mermaid entitled Siren and Triton. Like the landscape Prometheus, that work arose from a formative period this man spent reinterpreting Arnold Bocklin. Another painting by him features a marble torso juxtaposed with a characteristic banana bunch, as well as a background locomotive this artist frequently depicted passing through Montparnasse station. This artist of The (*) Uncertainty of the Poet is best known for painting a girl playing with a hoop before a single looming shadow. For 10 points, name this metaphysical artist of Mystery and Melancholy of a Street.

SOLUTION:
Fine Arts