Two Energy States The magnetic fields of the spinning nuclei will align either with B state the external field,or against the field. A photon with the right Bo hv=△E amount of energy can be absorbed and cause the a state spinning proton to flip. => Copyright2005 Pearson Prentice Hall,Inc Chapter 13 5Chapter 13 5 Two Energy States The magnetic fields of the spinning nuclei will align either with the external field, or against the field. A photon with the right amount of energy can be absorbed and cause the spinning proton to flip. =>