chemical reaction

American  

[kem-i-kuhl ree-ak-shuhn] / ˈkɛm ɪ kəl riˈæk ʃən /

noun

1. Chemistry. reaction.

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chemical reaction British  

noun

1. a process that involves changes in the structure and energy content of atoms, molecules, or ions but not their nuclei Compare nuclear reaction

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chemical reaction Cultural  

1. A process in which atoms of the same or different elements rearrange themselves to form a new substance. While they do so, they either absorb heat or give it off.

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Etymology

Origin of chemical reaction

First recorded in 1780–90

Example Sentences

In other words, continuing to cool the tank could slow the chemical reaction in a way that avoids an explosion.

From Los Angeles Times • May 23, 2026

Hydrogen sulfide smells like rotten eggs and can be produced by a chemical reaction and by some organic material, such as sewage.

From The Wall Street Journal • Apr. 22, 2026

Form’s iron-air batteries generate electricity through a chemical reaction involving oxygen, water and iron powder that mimics how old pieces of metal gather rust.

From Barron's • Feb. 24, 2026

Industrial catalysts -- substances that reduce the amount of energy required for a given chemical reaction -- help manufacturers boost reaction speed, yield or efficiency when producing key materials.

From Science Daily • Nov. 21, 2025

“Pressure brings it up. It results from a chemical reaction in the lungs when water mixes with air and mucus.”

From "Snow Falling on Cedars: A Novel" by David Guterson

Related Words

• vicious circle