chain reaction

noun

1. Physics. a self-sustaining reaction in which the fission of nuclei of one generation of nuclei produces particles that cause the fission of at least an equal number of nuclei of the succeeding generation.
2. Chemistry. a reaction that results in a product necessary for the continuance of the reaction.
3. a series of events in which each event is the result of the one preceding and the cause of the one following.

chain reaction

noun

1. a process in which a neutron colliding with an atomic nucleus causes fission and the ejection of one or more other neutrons, which induce other nuclei to split
2. a chemical reaction in which the product of one step is a reactant in the following step
3. a series of rapidly occurring events, each of which precipitates the next

chain reaction

1. A process in which the result of one event triggers another event, usually of the same kind, which in turn triggers yet another event, so that the overall reaction tends to be self-sustaining. Nuclear fission reactions are chain reactions, in which the splitting of an atomic nucleus releases neutrons that penetrate other nuclei, causing them to split. The spread of heat through a substance is also a chain reaction, as fast-moving molecules in a hot part of the substance collide with neighboring molecules, passing on their kinetic energy to them, thereby making more of the substance warmer.
2. See more at fissionSee Note at nuclear reactorSee also kinetic theory

chain reaction

1. In chemistry and physics , a self-sustaining series of reactions. In a chain reaction in a uranium -based nuclear reactor , for example, a single neutron causes the nucleus of a uranium atom to undergo fission . In the process, two or three more neutrons are released. These neutrons start more fissions, which produce more neutrons, and so on.

Notes

Figuratively speaking, any group of events linked so that one is the cause of the next can be called a “chain reaction.”

Word History and Origins

Origin of chain reaction¹

First recorded in 1925–30

Idioms and Phrases

A series of events in which each influences or gives rise to the next event, as in If one person collects substantial damages by suing a company, you can expect a chain reaction of such lawsuits . The term originated in the physical sciences, first (1920s) chemistry and later (1940) physics; in the latter it denotes a process of nuclear fission. By the 1940s it had been transferred to more general use.

Example Sentences

This sets off a chain reaction of events culminating in the creation of a “polar vortex” with more extreme cold, storminess and snow.

From Salon

The England prop's social media post suggesting the haka was "ridiculous" and should be "binned", kicked off the expected chain reaction of comment and condemnation.

From BBC

While power cuts are not unusual in Cuba, the failure of its biggest power plant last week triggered a chain reaction which saw the nation plunged into darkness.

From BBC

Two different British solutions to the long-running Irish problem backfired simultaneously, leading to the political equivalent of an uncontrolled chain reaction.

From Salon

When Grady finds Ashley’s body the next day, the subsequent quest for answers sets off a chain reaction of recrimination and revelations.

From Los Angeles Times

Related Words

• chemical reaction
• vicious circle