A reactivity series is a list of metals which are arranged in the order of their decreasing activity. This means the metal at the top of the series is the most reactive and the metal at the bottom of the list is the least reactive metal.

To develop a reactivity series, take pieces of different metals (e.g., iron, copper, zinc etc) and the salt solutions of those metals (i.e., iron sulphate, copper sulphate, zinc sulphate etc).

Add a metal piece to a different metal salt solution. Check for any colour changes in the solution or to the metal piece and record your observations.

One can tell that for metals A and B if the following reaction occurs,

metal A + salt solution of B → metal B + salt solution of A

then, metal A is more reactive than B. Similarly by trying out various combinations of metals with metal salt solutions, one can create a reactivity series.