Why do products of a chemical reaction have different properties from the reactants?

In physical science, a chemical reaction is a process that converts one or more substances, known as reactants, into different substances called products. The reason products possess different properties than the reactants is that the reaction involves the rearrangement of the constituent atoms of the reactants to create entirely new substances.12

During this process, the valence electrons of the participating atoms interact to form new chemical bonds, such as ionic bonds or covalent bonds. Because the physical and chemical properties of a substance are determined by its specific molecular structure and the way its atoms are bonded, the resulting products exhibit characteristics that are distinct from those of the original reactants. For example, the properties of carbon dioxide are fundamentally different from those of pure carbon and oxygen. While the total mass of the system is generally conserved in chemical reactions, the identity of the substances changes due to this structural reorganization.345627