Answer:
The balanced equation must be:
2Na + MgF₂ → 2NaF + Mg
Explanation:
You see that you have 2F in the reactant side, that's why we add 2, to the stoichiometry of the sodium fluoride.
So now, we have 2 moles of NaF. Therefore we need to add 2 to the sodium on the reactant side.
The equation is now balanced.
2 Na reactant side → 2 Na product side
1 Mg reactant side → 1 Mg product side
2 F product side → 2 F product side
