A student sets up a simple chemical cell using two different metal electrodes dipped into an electrolyte.
The list below shows the metals available to the student, in order of their reactivity:
Which two metal electrodes from the list should the student use to produce the greatest voltage?
Give one reason for your answer.
If the student first measures the voltage using zinc and copper electrodes, and then replaces the zinc electrode with magnesium, describe and explain the change in the measured voltage.