Can a metal displace any of the metals which are lower in the reactivity series?
Yes, a metal can displace (replace) any of the metals below it in an activity series.
The metals in an activity series are listed in decreasing order of reactivity. A more reactive metal will displace (replace) a less reactive metal in an activity series. So, yes, a metal can displace (replace) any metal that is below it in an activity series.
The video shows an experiment to determine the placement of three different metals (Cu, Zn and Mg) on the activity series.
Video from: Noel Pauller"