A chemical reaction does not involve: (1) Formation of new substances having entirely different properties than that of the reactants. (2) Breaking of old chemical bonds and formation of new bonds (3) Rearrangement of atoms of reactants to form new products (4) Changing of the atoms of an element into those of another element to form new products.

Answer: (4) Changing of the atoms of an element into those of another element to form new products

• A chemical reaction is where the bonds within the reactant molecules are broken and new bonds are formed within the molecules of the product in order to form a new material.
• A chemical reaction is a mechanism that takes place when two or more molecules interact to produce new products.
• A reaction between two atoms or ions or molecules may take place and a new bond is formed and no atom is destroyed or created, but reactants form a new substance.