High-precision mass and charge radius measurements on ;{17-22}Ne, including the proton-halo candidate 17Ne, have been performed with Penning trap mass spectrometry and collinear laser spectroscopy. The 17Ne mass uncertainty is improved by factor 50, and the charge radii of ;{17-19}Ne are determined for the first time. The fermionic molecular dynamics model explains the pronounced changes in the ground-state structure. It attributes the large charge radius of 17Ne to an extended proton configuration with an s;{2} component of about 40%. In 18Ne the smaller radius is due to a significantly smaller s;{2} component. The radii increase again for ;{19-22}Ne due to cluster admixtures.