Activity series — Science definition
A ranked list of metals from most to least reactive, used to predict whether a single-replacement reaction will actually happen.
Where it is taught
- Types of Reactions — Reactions, Moles & Composition, Physical Science: Chemistry, Grade 11
Questions using activity series
Problem 1
In the activity series, a more reactive metal replaces a less reactive one. Which single-replacement reaction will actually occur?
- Cu + ZnSO₄ → CuSO₄ + Zn (copper is less reactive than zinc)
- 2H₂O → 2H₂ + O₂
- N₂ + 3H₂ → 2NH₃
- Zn + CuSO₄ → ZnSO₄ + Cu (zinc is more reactive than copper)
Answer and explanation
Zn + CuSO₄ → ZnSO₄ + Cu (zinc is more reactive than copper)
Zinc sits above copper in the activity series, so zinc displaces copper — the reverse would not happen, and the other two are not single-replacement reactions.
Taught alongside
- synthesis reaction
- decomposition reaction
- single-replacement reaction
- double-replacement reaction
- combustion reaction