Question

How do you compare ionic radii?

Answer 1

Well, you have to have some data first....

Explanation:

And I have used this illustration before....

The units are in `"picometres"-=10^-12*m`. Because atomic radii are reasonably defined by the radius of the valence, the outermost electron, and thus with RESPECT TO THE PARENT ATOM, CATIONS are SMALLER (because they have been OXIDIZED), and ANIONS ARE LARGER (cos' they have been reduced).