reactivity
Americannoun
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the quality or condition of being reactive.
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Chemistry. the relative capacity of an atom, molecule, or radical to undergo a chemical reaction with another atom, molecule, or compound.
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Physics. a measure of the deviation from the condition at which a nuclear reactor is critical.
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Immunology. the ability of an antigen to combine with an antibody.
Other Word Forms
Etymology
Origin of reactivity
Vocabulary lists containing reactivity
Structure and Properties of Matter - Middle School
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Structure and Properties of Matter - Introductory
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Structure and Properties of Matter - High School
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The study found that the change in reporting dramatically reduced investors’ reactivity to market volatility, and a corresponding increase in their willingness to invest in riskier funds.
From MarketWatch • May 2, 2026
Paris police chief Patrice Faure paid tribute to "the reactivity and the mobilisation" of the investigators that led to the arrest of the suspect.
From Barron's • Dec. 27, 2025
The team suspected that choosing the correct ligand might unlock reactivity with alkyl ketones.
From Science Daily • Nov. 26, 2025
“We told Jack we needed a special person to handle this dog,” says Padilla, referencing Felisha’s fear-based reactivity.
From Los Angeles Times • Jul. 21, 2025
Too much reactivity and we would spontaneously combust.
From "The Gene" by Siddhartha Mukherjee
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.