Task: Text Categorization
Input (English): In an air column with one end closed, the wavelength of the first harmonic equals this multiple of the length of the air column. The magnetic permeability constant equals this coefficient of pi times ten to the negative seventh, and a typical Wheatstone bridge contains this many (*) resistors. The Stefan-Boltzmann law relates the power of blackbody radiation to this power of temperature. Maxwell names a set of this many equations governing electromagnetism, which is one out of this many fundamental forces in nature. For ten points, identify this number equal to the atomic mass of an alpha particle, which contains 2 protons and 2 neutrons.
Output (English): Science