How does the ionic radius of a typical metal compare with its atomic radius?
Metals are electron-rich, reducing materials; they are typically
And given the fact that the electrons come from the valence shell of the metal, the ionic radius of the resultant ion must be substantially smaller than the atomic radius.
On the other hand, oxidizing elements, such as fluorine and oxygen, should display substantially greater ionic radii given that they accept electrons into their valence shells. You should look at a text for confirmation by means of actual data.