Ranking anions/cations

[Karina Vasquez 1D]

When ranking say anions from least to greatest polarizability how does the charge determine where it would be placed when ranked? For example, ranking I-, Cl-, S2-, P3- how does the charge determine which of S2- and P3- will be ranked first (least to most polarizable)?

[Chem_Mod]

S2- and P3- have the same number of electrons. However, S has a greater number of protons than P. This means the electrons held by S experience a greater attractive force to the nucleus of the S ion than the electrons held by P, making it harder to distort the electron cloud away from S2-. Thus P3- is more polarizable than S2-

[Kguox1B]

Today in the review session, they said that when in the same row, charge becomes the determinant of which one is greater.