2Fe (s) + O2 (g) → 2FeO (s)

To which category does this reaction belong?

2Fe + O2 = 2FeO

this reaction belong a combustion reaction

a combustion reaction involve a reaction between a substance and oxygen. the reaction above is a combustion reaction because the reaction involve the reaction of iron (Fe) with oxygen and release large amount of energy and therefore

2Fe + O2 = 2FeO is a combustion reaction