There are different types of chemical reactions. Precipitation reactions produce insoluble substances (e.g., double replacement). The transfer of electrons between atoms is a reduction-oxidation (redox) reaction (e.g., single-replacement combustion, synthesis, decomposition). Some acid/base reactions involve the transfer of hydrogen ions.
Materials exist throughout our physical world. The structures of materials influence their physical properties, chemical reactivity and use.
There are several ways in which elements and/or compounds react to form new substances and each reaction involves energy.