\textbf{212 --} $0.6$ mol of which metal ion reacts with fluoride ion to form $46.8$ grams?
$$(\text{Ga} = 70\ ,\ \text{Ca} = 40\ ,\ \text{Al} = 27\ ,\ \text{Mg} = 24\ \text{ and }\ \text{F} = 19 : \text{g.mol}^{-1})$$
(1) Al \hfill (2) Mg \hfill (3) Ca \hfill (4) Ga
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