Chain Reaction Definition in Chemistry and Physics

What Is a Chain Reaction in Science?

Matches chain reaction
In a chain reaction, one action leads to another and another.

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In science, a chain reaction is a series of reactions where the products contribute to the reactants of another reaction without outside influence. The idea of chain reactions was introduced by German chemist Max Bodenstein in 1913 in reference to chemical reactions.

Chain Reactions Examples

A nuclear chain reaction is a fission reaction where the neutrons generated by the fission process go on and initiate fission in other atoms.

The chemical reaction between hydrogen gas and oxygen gas to form water is another example of a chain reaction. In the reaction, one hydrogen atom is replaced by another as well as two OH radicals. The propagation of the reaction can lead to an explosion.

Chain Reaction Steps

A typical chain reaction follows a sequence of steps:

  1. Initiation: Active particles form that serve as the basis for the reaction.
  2. Propagation: Active particles react with each other and may serve as catalysts to perpetuate the cycle.
  3. Termination: The active particles lose their activity, slowing and ending the reaction.