A chain reaction is a process where one event or reaction triggers another, creating a self‑amplifying series of steps that can continue on its own until something stops it.

Quick definition

  • In everyday language, a chain reaction is a series of linked events where each one sets off the next, like falling dominoes.
  • In science, it is a sequence of chemical or nuclear reactions where reactive products from one step cause further reactions of the same kind, often becoming self‑sustaining.

How it works (simple picture)

Think of a line of dominos: push the first, and each falling piece knocks over the next.

In a chain reaction:

  1. There is an initiation step that starts things off (like pushing the first domino).
  1. Propagation steps follow, where each result creates new “active” particles or changes that continue the sequence.
  1. A termination step eventually stops the process, for example when fuel, reactants, or triggers run out.

Scientific examples

  • Chemical chain reaction: In certain reactions (like radical polymerization), reactive particles keep generating new reactive particles, so the reaction repeats many times until the materials are used up.
  • Nuclear chain reaction: In fission, one nucleus splits and releases neutrons; those neutrons strike other nuclei, causing more fissions, which can become self‑sustaining in a reactor or explosive in a bomb if not controlled.

Everyday life meaning

Outside science, people also use “chain reaction” to describe:

  • Economic or social cascades, where one decision or shock leads to a series of follow‑on effects.
  • Weather, technology failures, or online trends where one change triggers many others in sequence.

In short, “chain reaction” always carries the same core idea: one change sets off a connected, often accelerating series of further changes.

Information gathered from public forums or data available on the internet and portrayed here.