Final answer:
Mn⁷⁺ (Manganese 7+) has the largest particle size among the options provided.
Step-by-step explanation:
The species with the largest particle size among the options provided is Mn7+ (Manganese 7+).
Manganese can have different oxidation states, which correspond to the number of electrons gained or lost. In this case, Mn7+ has gained seven electrons, resulting in the largest particle size.