The Nilsson model of these objects explains the observation from rotational spectra that the majority of them are prolate. Wigner used random matrices to describe the distribution of energy-level spacings in the spectra of these objects. They're not molecules, but "isomers" of these objects are often metastable because relaxation is extremely spin-forbidden, and are labeled with an (15[1])"m." Interactions with the spin of (15[1])these objects, symbolized I, leads to (*) hyperfine structure. The semi-empirical mass formula predicts a peak (10[1])around A equals 56 for the binding energy of these objects. (-5[1])The existence of these structures was suggested by their scattering of alpha particles in (10[1])Rutherford’s (-5[1])gold foil experiment. For 10 points, name these structures consisting of protons and neutrons that lie at the center of atoms. ■END■ (10[2])