More reactive metals lose electrons easier and become ions in solution, whereas less reactive metals accept electrons easier in their ion form, becoming solid.
In displacement reactions, the solid metal is oxidised and the metal ions in solution are reduced. If these two terms a new to you, oxidation is the loss of electrons and reduction is the gain of electrons. Most people remember this with the help of the Oilrig pneumonic. Oxidation Is Loss Reduction Is Gain- OILRIG
For example, placing
Oxidation half equation:
Reduction half equation:
More reactive metals are oxidised easier than less reactive metals. Since