How do chemical reactions rearrange atoms to create new substances?

In a chemical reaction, substances known as reactants are converted into different substances called products by rearranging their constituent atoms.12

This process involves the breaking of existing chemical bonds between atoms in the reactants, which requires an input of energy. Once these bonds are broken, the atoms or molecular fragments are reassembled into new configurations, forming new bonds to create the products. Energy is released during the formation of these new bonds.1

Because the atoms are simply redistributed rather than created or destroyed, the total mass of the system remains constant throughout the reaction, a principle known as the conservation of mass. This fundamental process allows for the creation of new substances with chemical properties distinct from those of the original reactants.312