1. The problem statement, all variables and given/known data If protons with magnetic moment mu in the z direction are in a strong magnetic field of magnitude B in the z direction, what is the frequency f of radiation that will be absorbed by the proton as it transitions from parallel to antiparallel states? Express your answer in terms of mu, B , and Planck's constant h . 2. Relevant equations 3. The attempt at a solution E = mu * B h*f= mu * B f = (mu * B)h but I got wrong.. the feedback says that my answer is off by multiplicative factor.. please help me.. thanks..