Answer:
C. FeO2
Step-by-step explanation:
In a chemical equation, the reactants are the elements/compounds that combine to give a new chemical compound called the product. To do this, these elements/compound must overcome what is known as activation energy for the compound know as the product to be formed.
The direction of the arrow in the chemical compound shows the reactants and the products. Where the arrow is in both directions, the equation is said to be reversible.