Final answer:
The student incorrectly wrote FezF as the formula unit for Iron(II) fluoride. The correct formula unit is FeF2, which is obtained by crossing the charges and simplifying the subscripts.
Step-by-step explanation:
The correct formula unit for Iron(II) fluoride is FeF2. The student incorrectly wrote FezF, which is incorrect for multiple reasons. First, they did not cross charges correctly. The charge of Iron(II) ion is +2 and the charge of fluoride ion is -1. Therefore, the formula unit should have a subscript of 2 for the fluoride ion. Second, they used the wrong chemical symbol for iron. The correct symbol for iron is Fe, not Fez. Lastly, they did not simplify the subscripts. The correct formula unit should have the simplest ratio of atoms and ions.
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