Linked from
The 39 pages that link to Ion, each with the reason it gives.
Electrical conductorRelated: Ions carry current through electrolytes and other ionic conductors.
ReductionRelated: Electron gain can turn a neutral atom into a negatively charged ion.
RedoxRelated: Electron exchange often changes the charge of participating species.
Dissolved loadRelated: Many common components of dissolved load are charged ions.
Plasma recombinationRelated: Positive ions provide the charged partners that capture electrons.