All chemical compounds are either “endothermic” or “exothermic.”
For it was a new kind which contained an exothermic ingredient.
When carbon unites chemically with oxygen, it is an exothermic reaction that gives off heat as correlated energy.
exothermic ex·o·ther·mic (ěk'sō-thûr'mĭk) or ex·o·ther·mal (-məl)
Of or relating to a chemical reaction during which heat is released.
Of of relating to the external warmth of the body.
Relating to a chemical reaction that releases heat. Compare endothermic.