CT: Many energy sources commonly used by humans are forms of chemical energy. They are usually labeled “fuels.” The way to use the chemical energy in most fuels is by burning them, as we do with wood, natural gas, gasoline, coal, and others. When these fuels burn, they give off heat, because the chemical reaction called combustion is an exothermic reaction. That is, the reaction releases thermal energy in the form of heat.
Some chemicals contain a great deal of energy that can be released all at once. These chemicals are called explosives. For example, when dynamite explodes, its chemical energy changes very quickly into thermal and radiant energy and transfers from a potential state to a kinetic state.
S: http://www.energyeducation.tx.gov/energy/section_1/topics/forms_of_energy/chemical_energy2.html (last access: 11 February 2015)
N: 1. chemical (adj): 1570s, “relating to chemistry,” from chemic “of alchemy” (a worn-down derivative of Medieval Latin alchimicus; see alchemy) + -al. In early use also of alchemy. Related: Chemically.
energy (n): 1590s, “force of expression,” from Middle French énergie (16c.), from Late Latin energia, from Greek energeia “activity, action, operation,” from energos “active, working,” from en “at” + ergon “work, that which is wrought; business; action”.
Used by Aristotle with a sense of “actuality, reality, existence” (opposed to “potential”) but this was misunderstood in Late Latin and afterward as “force of expression,” as the power which calls up realistic mental pictures. Broader meaning of “power” in English is first recorded 1660s. Scientific use is from 1807. Energy crisis first attested 1970.
2. The energy liberated in a chemical reaction, as in the combustion of solid, liquid and gaseous fuels.
3. chemical energy, Energy stored in the bonds of chemical compounds. Chemical energy may be released during a chemical reaction, often in the form of heat; such reactions are called exothermic. Reactions that require an input of heat to proceed may store some of that energy as chemical energy in newly formed bonds. The chemical energy in food is converted by the body into mechanical energy and heat. The chemical energy in coal is converted into electrical energy at a power plant. The chemical energy in a battery can also supply electrical power by means of electrolysis.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=chemical+energy&searchmode=none (last access: 11 February 2015). 2. TERMIUMPLUS. 3. EncBrit – http://global.britannica.com/EBchecked/topic/108679/chemical-energy (last access: 11 February 2015).