If atoms are made up of smaller parts such as electrons why are atoms considered as the basic unit of matter

its first and third is your answer i did the qustion the fourth isnt right

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.