Which is the correct interpretation of the formula mgf2?

the lattice contains 1 magnesium ion for every 2 fluoride ions.

Explanation: is an ionic compound. It contains positive ions of Magnesium and  and negative ions of Fluorine. To balance the +2 positive charge of one magnesium ion, two (-1) negatively charged Fluorine ions are present. Hence, The correct interpretation of   is that the lattice contains 1 Magnesium ion for every 2 Fluoride ions.

i think that the answer is c

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.