Elemental reactions refer to the interactions between different chemical elements that lead to the formation of new substances. These reactions can occur in various forms, such as combustion, oxidation, and reduction. Each type of reaction involves the breaking and forming of chemical bonds, resulting in the release or absorption of energy. In nature, elemental reactions are essential for processes like photosynthesis, where plants convert sunlight into energy, and respiration, where organisms break down food for energy. Understanding these reactions helps scientists develop new materials and energy sources, contributing to advancements in fields like chemistry and environmental science.