Final answer:
Manganese (II) iodide contains one manganese ion (Mn2+) and two iodide ions (I−) for each formula unit, balancing the charges to make the compound neutral.
Step-by-step explanation:
The question asks for the number of ions in manganese (II) iodide. Manganese (II) iodide is comprised of one manganese ion (Mn2+) and two iodide ions (I−), because the manganese ion has a +2 charge and each iodide ion has a -1 charge. In a neutral compound, the total charge must be zero, so the two -1 charges from the iodide ions balance out the +2 charge of the manganese ion.
This means that for each formula unit of manganese (II) iodide, there is one manganese ion and two iodide ions. If you have a sample of manganese (II) iodide consisting of multiple formula units, you would have an equal number of manganese ions to formula units and twice as many iodide ions as formula units.