Transverse elastic and inelastic form factors for low-lying levels in 117Sn have been measured by 180° electron scattering in the momentum transfer range qeff=1.1–2.4 fm-1. The simple independent-particle model fails to account for these data, predicting form factors that are much too large. In better quantitative agreement with the data are the results of more detailed calculations that allow for configuration mixing of valence nucleons, as well as first-order core polarization. As in the similar case of 205Tl, these calculations successfully predict the presence of a deep diffraction minimum observed in the intermediate q region of the elastic M1 form factor. Nevertheless, the overall description of the data by the detailed calculations remains quantitatively unsatisfactory. A more complete understanding of these data may rely upon the consideration of multiparticle-multihole configurations outside the 0ħω basis space.