Step-by-step explanation:
The reaction can be said to be a single replacement reaction if one substance in a chemical reaction is replacing another one.
For example:
A + BC → AC + B
In such reactions there is a replacement of a metallic ion in solution by a metal atom higher in the activity series than the metal in solution.
The relative positions of the two elements in the activity series provides the driving force for a single replacement reaction. If one element that is to replace another in a compound is more active, the reaction will occur. If it is less reactive, there will be no reaction.