1. the quality or state of being reactive; tendency to react readily to stimuli or changes
2. the relative capacity of an atom, molecule, or radical to undergo a chemical reaction
Usage: chemistry
3. the state of a nuclear reactor with respect to the balance between neutron production and absorption
Usage: nuclear physics

Examples

• The patient’s emotional reactivity made therapy challenging.
• High reactivity to stress can affect one’s health.
• Sodium has high chemical reactivity with water.
• The metal’s reactivity increases when exposed to oxygen.
• Scientists measured the reactivity of different compounds.
• The reactor’s reactivity was carefully monitored.
• Her skin showed reactivity to the new cosmetic product.