The meaning of REACTION is the act or process or an instance of reacting. How to use reaction in a sentence.

Reaction Time Test When the red box turns green, click as quickly as you can. Click anywhere to start. Statistics About the test This is a simple tool to measure your reaction time. The average (median) …

Define reaction. reaction synonyms, reaction pronunciation, reaction translation, English dictionary definition of reaction. n. 1. a. A response to a stimulus. b. The state resulting from such a response. …

Online reaction time test. Click as soon as the field turns green. Average and best time, attempts, CSV export, and built‑in self‑tests.

REACTION definition: 1. behaviour, a feeling or an action that is a direct result of something else: 2. someone's…. Learn more.

Apr 17, 2026 · A chemical reaction is a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either chemical …

A chemical reaction is a process in which two substances combine together chemically to form another substance. Ozone is produced by the reaction between oxygen and ultraviolet light.

Apr 3, 2025 · Allergic reactions are symptoms that happen after you touch, inhale or eat something you’re allergic to. Common causes include foods, plants, medications and pets.

Reaction Look up reaction in Wiktionary, the free dictionary. Reaction may refer to a process or to a response to an action, event, or exposure.

Definition of reaction in the Definitions.net dictionary. Meaning of reaction. What does reaction mean? Information and translations of reaction in the most comprehensive dictionary definitions resource on …