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.

This quantity for an atomic nucleus is determined using Weizscker's [VAHYTS-zek-uhrs] formula. The no hair theorem states black holes are completely characterized by their angular momentum, charge, and this quantity. The oscillation period of a spring equals two pi times the square root of this quantity over the spring constant. The theoretical value of this quantity for gluons is zero. Linear momentum equals this quantity times velocity. For 10 points, name this quantity measured in kilograms.
Science

In one myth this deity laid the egg that would become the world and his association with the equinoxes led to his epithet as the god of balance. His center of worship was at Khmunu and one of his wives, Seshat, was the inventor of writing. He carried the eye of Ra in his role as messenger, but is better known for weighing the hearts of the deceased in his role as judge of the dead. Often depicted as a baboon, he hid Horus from Set after the latter killed Osiris and returned Tefnut to Ra's fold. FTP name this Egyptian god of scribes, wisdom, and the moon, most commonly depicted with the head of an ibis.
Social Science

Differentiating this quantity with respect to the auxiliary function can be used to find the Feynman amplitude, while performing a Wick rotation on a Feynman path integral creates a function analogous to this one. Partially differentiating it twice with respect to alpha is equal to the variance in the number of particles when beta and volume are constant. Multiplying its partial derivative with respect to volume at constant chemical potential and beta is equal to the pressure, while it serves as the normalizing constant for the Gibbs measure. This function is equal to the sum over all microstates of e raised to the negative beta times the energy of that microstate, and it is usually defined for a canonical ensemble. For 10 points, name this function, which can be used to express all the properties of a thermodynamical system.
Science