Which. of the following. best represents a chemical. reaction?

A chemical reaction is best represented by a process where reactants transform into products through the breaking and forming of chemical bonds. For example, when hydrogen gas reacts with oxygen gas to form water, represented by the equation 2H₂ + O₂ → 2H₂O, this illustrates a clear change in substance and composition. Other indicators of a chemical reaction include color change, gas production, or temperature change.