Final answer:
Iron (II) is not reactive enough to displace sodium from sodium fluoride, so the single displacement reaction described does not occur, and therefore no balanced chemical equation can be written.
Step-by-step explanation:
The question asks to write a balanced chemical equation for iron (II) undergoing a single displacement reaction with sodium fluoride. A single displacement reaction involves a more reactive element displacing a less reactive one from its compound. In this case, however, iron (II) is not reactive enough to displace sodium from sodium fluoride. Thus, the reaction proposed does not occur, and it’s not possible to write a balanced chemical equation for this non-existent reaction.
If we were to consider a hypothetical situation where iron could displace sodium, the unbalanced equation would look like something along the lines of Fe + 2NaF → FeF₂ + 2Na, but this does not represent a real chemical reaction as per the reactivity series of metals where iron is less reactive than sodium.