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: Flaws in Schrodinger's equation or Bohr's formula can be corrected by introducing this value measured in multiples of a unit called the Dirac h, or h-bar. It was first proposed by Samuel Goudsmit and George Uhlenbeck to explain the spectra of light emitted by atoms of alkali metals. Calculated for complex nuclei by taking the vector sum of the intrinsic values for the constituent particles and their orbital angular momentum, it is zero for nuclei with even numbers of neutrons and protons in their ground states and for pions, while for electrons, neutrons, and protons the multiple involved is 1/2. FTP, what is this measure of the amount of angular momentum associated with a subatomic particle or nucleus
A:
Science