Contents

Activity series of metals

Metals Metal Ion Reactivity
K K+ reacts with water
Ca Ca2+
Na Na+
Mg Mg2+ reacts with acids
Al Al3+
Zn Zn2+
Fe Fe2+
Ni Ni2+
Sn Sn2+
Pb Pb2+
H2 H+
Cu Cu2+ highly unreactive
Hg Hg2+
Ag Ag+
Au Au3+

Metals are listed in decreasing ease of oxidation, or increasing ease of reduction. A metal can replace metals listed below it in the activity series, but not above. For example, sodium is highly active and thus able to replace hydrogen from water:

2 Na (s) + 2 H2O (l) -> 2 NaOH (aq) + H2 (g)
Metals that can replace hydrogen within acids but not water are listed in the middle of the activity series, for example zinc replaces hydrogen in sulfuric acid:
Zn (s) + H2SO4 (aq) -> ZnSO4[?] (aq) + H2 (g)

The activity series has applications in electrochemistry, where two dissimilar metals are chosen as electrodes of a battery.