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exothermic

/ˌek.səˈθɜː.mɪk/
IELTSAcademic
adjective

An exothermic reaction gives out heat to the surroundings. It becomes warmer because energy leaves the process as heat.

  • Burning wood is an exothermic reaction.
  • The flask felt hot after the exothermic reaction.
  • Some exothermic changes happen very quickly.

Adinary Nuance

Exothermic is more specific than "hot" or "warm." It describes a scientific process that releases heat, not just something with a high temperature. It is the opposite of endothermic, which takes in heat. In chemistry writing, choose exothermic when you want to describe the reaction itself, not the object.

In other languages

Vietnamese
tỏa nhiệt
Spanish
exotérmico
Chinese
放热的
Japanese
発熱性の
Korean
발열성의

Etymology

From Greek exo- meaning “outside” and thermē meaning “heat.” The word entered scientific English in the late 19th century.

Common phrases

exothermic reactionexothermic processexothermic change

Synonyms

Related words

Frequently asked questions

Is exothermic the opposite of endothermic?
Yes. Exothermic reactions release heat, while endothermic reactions absorb heat.
Is exothermic used only in chemistry?
It is most common in chemistry, but it can also describe other heat-releasing processes.
Can I say an exothermic reaction is hot?
Yes, but exothermic is more precise. It explains why the reaction gets hot.