# How do you balance and translate this reaction: Fe(s) + O_2(g) -> Fe_2O_3(s)?

$2 F e \left(s\right) + 3 {O}_{2} \left(g\right) \to 2 F {e}_{2} {O}_{3} \left(s\right)$
This reaction can be written in words as iron III combining with oxygen gas to form iron III oxide. You know it is iron III, not iron II, because oxygen is always ${O}^{2 -}$, so the only way that $F {e}_{2} {O}_{3} \left(s\right)$ is neutral is if the iron has a charge of $3 +$.