Chemical Energy Definition and Examples

What Is Chemical Energy?

Wood is a source of chemical energy, which may be released during a combustion reaction.
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Chemical energy is the energy contained in the internal structure of an atom or molecule. It is a measure of a substance's capacity to transform into another substance via a chemical reaction. This energy could be in the electronic structure of a single atom or in the bonds between atoms in a molecule. Chemical energy is converted into other forms of energy by chemical reactions.

Examples of substances that contain chemical energy include:

  • Wood
  • Food
  • Gasoline
  • Batteries

Chemical energy is released or absorbed as chemical bonds are broken and reform. It is a misconception that a substance always releases more energy than it absorbs! Chemical energy is calculated as the difference between the energy of the products and reactants. This may be measured using a calorimeter or calculated based on the bond energies of the chemical bonds.


  • Schmidt-Rohr, K (2015). "Why Combustions Are Always Exothermic, Yielding About 418 kJ per Mole of O2". J. Chem. Educ92: 2094–2099.
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Helmenstine, Anne Marie, Ph.D. "Chemical Energy Definition and Examples." ThoughtCo, Aug. 27, 2020, Helmenstine, Anne Marie, Ph.D. (2020, August 27). Chemical Energy Definition and Examples. Retrieved from Helmenstine, Anne Marie, Ph.D. "Chemical Energy Definition and Examples." ThoughtCo. (accessed March 22, 2023).