If atoms from two different elements react with each other, a compound is formed. During such a reaction, electrons from atoms might be shared or transferred to form new chemical bonds. For example, sulfur reacts with iron when heated together to form iron sulfide, a compound.
Atoms that react with each other in a chemical reaction are called reactants. The atoms that are produced in the reaction are called products. There are no new atoms that are created or destroyed during a chemical reaction. The atoms that are in the products come from the reactants.Learn more about Atoms & Molecules