🧪ap chemistry review

Half-life (t₁/₂)

Written by the Fiveable Content Team • Last updated August 2025
Verified for the 2027 exam
Verified for the 2027 examWritten by the Fiveable Content Team • Last updated August 2025

Definition

The time required for the concentration of a reactant to decrease to half its initial value; for first-order reactions, half-life is constant and independent of initial concentration.

AP course connection

Topic 5.3: 5.3 Concentration Changes Over Time

Unit 5

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