A student sets up a simple electrochemical cell to measure the potential difference using different components, as shown in the diagram.
Which combination of Electrode A, Electrode B, and Electrolyte will produce a non-zero reading on the voltmeter?
Electrode A: Nickel; Electrode B: Nickel; Electrolyte: 1.0 mol dm−31.0\text{ mol dm}^{-3}1.0 mol dm−3 potassium nitrate solution
Electrode A: Zinc; Electrode B: Copper; Electrolyte: Distilled water
Electrode A: Magnesium; Electrode B: Iron; Electrolyte: 1.0 mol dm−31.0\text{ mol dm}^{-3}1.0 mol dm−3 glucose solution
Electrode A: Iron; Electrode B: Copper; Electrolyte: 1.0 mol dm−31.0\text{ mol dm}^{-3}1.0 mol dm−3 sodium chloride solution