A strong correlation is shown to exist throughout the periodic table : etween theZ2dependence of the electronic stopping cross-sections for4He ions of a given velocity and theZdependence of the atomic potentials at a certain radius. An empirical formula is presented which allows the extrapolation of stopping cross-section data for any ion at a given velocity in some elements, to elements for which experimental data are not available. This study covers the energy interval 100 <E/m< 1000 keV/amu.