What is the reactant of 2Fe2O3 = 4Fe + 3O2

It depends on the direction of the arrow.

If the arrow goes like this ---> the reactant would be 2Fe2O3

If the arrow goes like this <--- the reactants would be 4Fe + 3O2

samuel de champlain. in 1608, king henry iv sponsored pierre dugua, sieur de mons and samuel de champlain as founders of the city of quebec with 28 men. this was the second permanent french settlement in the colony of canada.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.