In contrast, in the case of the right figure (Cs ions), the diffusion of Pt ions to the offshore is suppressed and Pt ion re-deposition is more likely to occur, resulting in suppressed Pt dissolution.

Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions ...