In the Bohr model of the hydrogen atom, an electron in the ground state orbits a proton at a radius of 5.29 × 10–11 m. In a reference frame in which the orbiting electron is at rest, the proton circulates about the electron at a radius of 5.29 x 10–11 m with the same angular velocity as that of the electron in the reference frame in which the proton is at rest. Consequently, in the rest frame of the electron, the magnetic field due to the motion of the proton has the same magnitude as that calculated in Problem 5. The electron has an intrinsic magnetic moment of magnitude μB. Find the energy difference between the two possible orientations of the electron's intrinsic magnetic moment, either parallel or antiparallel to the magnetic field due to the apparent motion of the proton. (This energy difference is readily observed spectroscopically and is known as the fine structure splitting.)